View Full Version : Need help from mega air experts
HoustonDMax
05-08-2003, 06:36
Installed JK Mega filter weekend before last, post oem. Installed di-electric grease on all hose connections. Matter of fact, stock connections rotate, but will not slide on the pipe. JK indicated this should be OK. Full fuel tank.
Approximately 225 miles on tank, had a start and then die after a few seconds episode. Crank again, no start. Leaving garage, so no biggie. Opened Mega bleeder, pumped quite a few primer pumps to get fuel to run out. Started right up then.
Another 100 miles on same tank, another start and then die after a few seconds. This time, in grocery store parking lot, blocking traffic, as I had started to move before it died. Quickly open hood, pump primer 20 times, without opening bleeder. Started after a few seconds of cranking, and ran fine.
Another 10 miles, and another sart and die after a few seconds. Again in parking lot, blocking traffic again. Quick twenty primer pumps and about twice as much cranking, and she fired.
Got home, and figured I would bleed her right. Took forty eight pumps to get fuel out of the Mega filter bleeder. Checked factory bleeder next, and got fuel with first pump.
I will say that I had a problem close to a year ago with a no start, when I had parked overnight after the low fuel light had come on. Primer pumping got her to fire right up. From that time on, after seeing warnings on TDP that running down to the low fuel light came on was not a good idea, anytime I get down fairly low, I fill up. No more stall problems till I installed the Mega filter.
Figure I am probably one of these lucky ones that has a lot of air, just like I am one of the lucky ones that has a problem with the Juice in rain.
Anyway, I think the value of better filtering is good. However, I can not be stalling on a regular basis, nor do I want to wear out my primer pump. As soon as school is out, am hooking up the 5th wheel, and taking the family to Disney World. Don’t want to stall heading over the bridge on Lake Charles, crossing the swamp in Louisiana, crossing Mobile Bay, etc.
For those that are working on installing a bleeding system, or that have a lot of experience in dealing with this issue, JK, a bear, chuntag95 (Chris), jbplock or anyone else, would you share a little more detail on your solution. I follow both Chris and Bill’s line of thought, except where you are planning on grabbing the return. I have seen discussion on hitting it at two different spots. Since you both have posted great pictures, could you perhaps shoot one of that area.
Chris, what are you using for reverse flow prevention?
Got a five hundred mile road trip this weekend, so I will see how she performs. I would then like to fix the problem over the following weekend.
Sorry for the long post, but I really need some help here.
Thanks in advance for the help,
HoustonDMax
I wonder if the Mega filter is just a bear to get all of the air out of initially?
Maybe the filter media is simply not letting the air rise until it gets shaken up during driving? Maybe after time the air will stop?
Try rapping the side of the filter with a rubber mallet a few times (gently now ;) ), not when you're in the wrong mindset.
Does more air suddenly appear?
Well this is just a WAG- but do you think one of the new filters might have gotten plugged somehow?
dielectric grease maybe?
When you mechanically pump the fuel, it runs.
During normal operation it doesn't run. If there is a leak in the new hoses or fittings, obviously air is the problem. But in the absence of a leak,
I'd look for a restriction. Something blocking the fuel.
zip
I haven't bled mine in quite a while.
I will say that I suggest that you pump up the primer BEFORE opening the bleeder as the system will stand with 2"hg so when you open the bleeder it will let air in.
chuntag95
05-08-2003, 08:05
Houston, We have a problem. :rolleyes: Sorry, I just couldn't resist. :D Actually, I think we also have a solution. I will be working on the auto bleeder this weekend and post pictures, part numbers, etc. As far as my check valve, I got it from M S C Direct.com. Unlike Grainger, the will sell to an individual. You just set up an account and BUY BUY BUY! tongue.gif I got the 1/8" check valve (brass) for the pump and I also bought a 1/4" and a 3/8" for the return line. I don't know if I will do the return line, but probably. I might temp it first with a bottle or something. Anyway, I think you will have to push a button in the cab instead of jump out, open the hood, pump like crazy while burning your arm on that STUPID heater line that I hit every dang time. :mad: Sorry, about getting off topic there.
I am at 170 since my last bleed. I will see if she has a problem in the next day or two. I have never had the stall problem except when I did a hose change and got a bunch of air in the line post bleed valve. I got through that cause I could see the problem.
If you want, shoot me an email chuntag95 at attbi dot com and I will send you all of the part numbers from MSC and others that I have for this project. Do you want with or without sight glass?
Chris
HoustonDMax,
I haven't had a no-start with the mega filter but I also haven't gone beyond 250-300 miles with out bleeding. I believe others have gone much longer with out bleeding and once I get done tinkering with the auto bleeder this weekend, I plan on just driving and not bleeding until I have a problem (if any). It sounds like your situation may be similar to Tommy's. He had no-starts after the MegaFilter install, which he subsequently fixed by replacing the QD's at the tank with 7/16 hose and clamps. You may also have a leak, but not necessarily in the same place. If there were a leak, the auto bleeder (if it ends up working) would not be the way to solve the problem. The auto bleeder would only be a convenient way of purging air/vapor trapped by the MegaFilter in a "healthy" system with out external leaks. The definition of a "healthy" system (with or with out circulation air/vapor) is also debatable. Like Chris, I will also post a complete description with PN's and results (good or not so good) for the auto-bleeder as soon as I have them.
smile.gif
Constant bleeding and auto bleeders?
I don't know about you guys. Flame me if you want but if it was me I'd be doing something drastically different.
Most vendors have money back guarantees. I assume JK does too. You're playing around with your fuel system and increasing the chance of problems down the road.
Add a filter..... great.
Anything you guys do after that just doesn't make a whole lot of sense to me.
It either works or it don't.
HoustonDMax
05-08-2003, 11:30
Appreciate the feedback.
I do pump several times before opening bleeder, in an attempt to not let air enter through the bleeder. I don't think it is a clog, or not having gotten all the air out initially; in any case, this weekends trip should flesh that out.
I will see what happens this weekend with my road trip, and go from there. Look forward to hearing what kind of success Chris and Bill have this weekend.
JK, or anyone else for that matter, correct me if I am wrong, but is the bleeder on the Mega on the input (dirty) side of the flow?
Oh, has anyone had a stall other than right after start, that they attribute to air?
Again, thanks!
HoustonDMax,
The MegaFilter Bleeder is on the dirty side.
Some people (Hoot) just don't get it :rolleyes:
It is NOT the filter's fault that it catches huge amounts of air that should NOT be present in the first darn place!
Further to that, each customer ordering the kit now receives a canned email making sure they understand what is happening BEFORE the order is processed...
TooMuchMuscle
05-08-2003, 13:33
Kinda funny... I am not trying to put people down and manny times thank people for the advance work they have done... but in this situation it seems kinda rediculous... bleed every 200-300 miles... that would mean that I would have to do that every night or every other night. Thats too much for me. What about the idea of filtering the fuel before entering the factory tank... I have a 45 gallon auxiliary tank and use that as my filling tank. From the aux tank I then pump fuel into my factory tank. But before going in my factory tank the fuel runs through two filters. Both filters are 2 micron and usually last 7,000 miles.
This system works great and probably filters better than splicing into the factory fuel lines. I like the idea of inline filters but dont like the idea of pumping every so often.
Also this... there are a lot of D-Max's on the road and only a small percentage of them on this site. I dont think that everyones injectors are wearing out... only a small percentage. I have seen too many diesels out there with high miles and original injectors... somethings funny. Filter before the tank and all will be fine.
Had to state my .02 cents
Sorry John. I had a long comeback but decided to let your customers deal with it.
No offence meant here :D :D but,
when it comes to air in the stock fuel system "ignorance is bliss" :D or maybe ... "out of sight, out of mind ?" :D
oh oh ... here comes the "filter war zone"
[ 05-08-2003: Message edited by: jbplock ]</p>
cmtndmax
05-08-2003, 13:56
TOOMUCHMUSLE I would like more info on your aux tank/filter setup.
I agree that it is kinda ridiculous, but people are missing the point here. The air is in the system BEFORE this filter. It should NOT be there.
NOW some of this air is possibly a product "outgassing" from the fuel, but not as much as some are experiencing. The real kicker is that lack of consistency in the whole deal. Some have tons of air, and others none. Some have none one day and tons the next. Some have this problem with the STOCK fuel system!
I could likely shave off the nipple to a nub like most filters, and rely on the threads to seal and chances are, the air will pass through the system. This may eliminate the no start situations, then again maybe not.
Time may prove that air in the Dmax fuel system does not have any major long term side effects, but I'm not willing to test this theory. I hear from the ones with injector problems, and let me tell you, when it rains it pours for these unfortunate individuals! Very seldom has one visit/replacement cured the problem...
For the record, I now have about 7k on my setup, and have yet to experience any air related starting or stalling issues. I do have air, but have gone 1000+ miles between bleeding, and quite honestly cannot remember when I last bled mine. I know it was at least a couple of weeks ago...
Mel,
IMHO, the road starts with the process described in the Helms manual for checking for air between the EDU aka FICM, and the OE filter head. FWIW, the factory primer consists of a pair of Vee rings under the plunger/cap. Quite simple, and I'm sure inexpensive...
cmtndmax
05-08-2003, 14:06
toomuchmusle email me if you don't what to post here cmtndmax@yahoo.com
Going on a 150 mile jaunt to Seattle today and be back on Monday.
We'll see how it does.
Went 3 days without bleeding and it quit on me today leaving work.
It really makes no sense how it can be a problem every morning then go 3 days and re appear.
A lot of the stuff we do is not only for the good of the vehicle but its fun too!
The Mega filter is not the cause of the problem its just bringing a characteristic of the Duramax to light.
I don't want to feed my engine a steady diet of air so we'll keep banging away till we get it licked.
If I used my truck to make my living etc I would wait till one of us solves the problem then decide whether to buy in or not.
Its a free country so make your decision and quit b****in. tongue.gif tongue.gif :rolleyes:
[ 05-08-2003: Message edited by: NWDmax ]</p>
Perhaps one of the Mega Filter owners could find out why their filters
trap air by contacting Baldwin directly and let us all know. The Mega
Filter looks like a great idea in theory, but it just does not seem practical
if you have to go to extraordinary means to get rid of collected air.
http://www.baldwinfilter.com/support/ser_eng.html
>>The Baldwin Service Engineering Department is recognized for its ability to help solve
customers' filtration problems and for creating continuing education programs to aid in
preventive maintenance. If there are any questions, please contact the Service Engineering
Group from 7:00 AM - 5:00 PM (Central). You can be easily directed to the Service
Engineering Group by dialing 800-822-5394 and following the instructions provided by the
automated attendant; speaking with the switchboard operator; dialing Service Engineering
directly at 308-237-9729; or sending an E-Mail to Service Engineering.
Dave Lewis
05-08-2003, 14:43
I think it's great that John's filter has exposed this air in fuel problem. I can tell you from working a great deal with pumps both low pressure and high pressure (40,000+ psi) that air is bad. On vane type pumps, cavitation is a death sentence for the pump. While our pumps might not be experiencing this (air in the fluid is not the same thing as cavitation) I can tell you that the less air the better. As far as the injector pump goes any air in the system will significantly decrease system performance. All of the high pressure systems I have designed have had a bleed valve on the high pressure side to release any trapped air. With air in the system the pump can't achieve maximum pressure output. This could be why we are seeing such a big difference in milage between trucks. I can tell you that on our high pressure pumps the fluid was required to be filtered to 1/2 micron. This is probably unrealistic for our application but it gives you an idea of how damaging dirt can be to high pressure pumps. Also as another note, repair of the system was basically supposed to be handled almost like a clean room operation. How many dealers do you think take these kind of measures. Sorry for rambling but IMHO air is just as bad as dirt get rid of both of them.
I have yet to install the mega filter because I am a little leery of the air issues.
John, didn't you take additional steps to eliminate the air entry source, such as hose and clamp replacement? It would be helpful for me, maybe for others, if you would list all of the steps again. Seems like the steps you took eliminated the problem on your truck.
If you would rather not list those steps here, please e-mail me: storerps at earthlink.net (replace the at and spaces with @). Thanks John.
Thanks to all who are working the issues and to Hoot for expressing his opinion.
Mark Bajus
05-08-2003, 15:20
If one wants to see what air in a diesel injection system CAN do, just go surfing on the ford diesel website under "cackle" to see how air in the 7.3l system contributes to low mileage, injector problems, low power, no start etc. Set aside a day or two to read it all! Now of course their system is different than the DMax system, but whats bad for one would seem logical to be bad for the other.
WhiteDuramax
05-08-2003, 15:40
Did you guys with the Mega Filter installed have problems before the filter install, with air?
JK -so you are saying that air is present in the current system and is getting by the factory filter but is bottling up in your mega filter?
I am interested in extra filtration but dont want to have air problems.
Mark Bajus,
Could you please give us a link to this "crackle" problem
experienced by Ford. Also, is this naturally occurring air
in the diesel fuel that is causing Ford the problems?
Dave Lewis,
Naturally occurring air in our diesel fuel is normal but I
cannot find any papers or studies that show that it
will harm our injectors or engines. Other than anecdotal
reports and claims..... please provide some evidence.
I also tried a search on our TDP and find no reference to
failure of injectors because of naturally occurring air in
our systems until the MEGA filter came into production.
[ 05-08-2003: Message edited by: 56Nomad ]</p>
56Nomad:
I am unable to access your Album at Community Webshots but would like to check out your Post OEM Racor filter installation.
Could you please e-mail me pictures of your installation .
Thanks much.
Swanny email: aswanny@hotmail.com
[ 05-08-2003: Message edited by: Swanny ]</p>
Mark Heiken
05-08-2003, 16:45
Just a thought here. I've been watching the filter issue and am looking at adding one. The reference to the 7.3 thing really got my attention. My Dmax engine changes tone alot lately. Running down road at steady speed 70-75 it runs quit as ever most of the time. Great throttle response and pulls hard. Sometimes tho it rattles more and response is not as good. This condition usually happens after a full throttle blast. Is it pulling air in when demand is greater and taking a while to get that air thru the system? Runnig poorer until that air is gone?
On the Mega Filter issue, is the filter adding enough more vacuum to the suction side to cause an air leak at a fitting that is marginal at best? Pulling air at that fitting may be easier than pulling fuel from the tank. If the tank is near empty that would seem to make it worse as it would take more suction to pull the fuel.
Just some ideas. I'm sure JK can shed more light on the filter causing more vacuum.
Let's see if I got this right ;)
Somehow a fuel filter system, by some design quirk, accidentally discovers that there is air present in the fuel and and is able to extract it.
Now the mad scientists are busy at work fiquring out how to isolate this air and contain it.
Finally, an elaborate containment vessel is being engineered to contain this errant gas and exploit it's presence.
.
.
.
On a more serious note, I would not want my truck continually gulping large amounts of air into the injection pump every time it stalls.
[ 05-08-2003: Message edited by: hoot ]</p>
Can any one explain chuntag95's experience showing significant air in his fuel system BEFORE he installed the Mega?
http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=005669&p=1
I'd like to suggest a few of the 'no air problem' crowd try the clear fuel line test and post their findings.
Well, there is no doubt that "leaks" could occur and do in some trucks ..... But 7 out of 10 that put on the Mega have discovered that they have OE leaks ??? I would think then there would have been more chuntag95 from the get go hanging around looking for help .....
I have an idea that I thought I would allow the crowd to disperse .... tongue.gif
Where is the Mega filters actual place in filter land, what application it was designed for, had a pump in front of it as oppose to a vacuum application with the Dmax ??? It surely isn't for the Dmax originally .....
So I ask what Baldwin filter number is it and what application was it intended for ???
MAC ====> :confused: as usual ...... ;)
[ 05-08-2003: Message edited by: mackin ]</p>
Sorry mdrag,
I'm happy with my system as is. I'm not ready
to experiment again tongue.gif
George said this....
Another point that may be relative is that in nearly every case when a secondary filter has been added, there has been a noticeable increase in perceived performance.. Is this the result of the elimination of entrained air, resulting in a more perfect fuel process?
George
I definately have an increase in performance since I installed the second 2 micron filter.
The Baldwin (MegaFilter) P/N is BF7635. Go to http://www.baldwinfilters.com/catalog.html, click on
OK, I have a question for JK.
I had my Mega filter installed locally about five or six hunderd miles ago.
I had NO air in fuel problems before the installation.
I'v had NO air in fuel problems since the installation.
I've experienced a 1 1/2 mgp increase with my first and only fill up after the Mega was installed.
I have had NO stalling or any other problems, it runs very well.
I have NOT bled anything since I had the Mega installed.
I am not worried.
Should I be? If so, why, and what should I do?
dmaxalliTech
05-08-2003, 19:12
I am leaning on the fence listening to all of this and have to keep wondering why I am not getting air in my system. I have been tempted to cut a small slit in my feed line just to introduce air and see what I would do about it.
I am impressed with the design that went into the system. JK must have spent a great deal of time in the design stages to make sure he had a good product. Someone with a reputation like his is not gonna produce subpar equipment. I think that most of you agree because just about everybody's sig's has JK.... this or that. I ordered two more kits today from JK to install on customers trucks that I service. I certainly would not recommend or install something I believe would give them problems, they are readers of TDP and we have talked in length regarding it. IIRC the Baldwin filter used is taken from off-highway mining applications on engines that run nearly 24/7. Of course, I must admit, that if I was getting air, I too would be tinkering to find out why and how. :D
dmaxalliTech
05-08-2003, 19:14
Felpa, write your local congressman and demand he change his views ;)
chuntag95
05-08-2003, 19:19
Houston,
Bill is correct in that the auto bleeder is a temporary fix or a bandaid so to speak. I think you have a leak and need to find it and eliminate it. The pump on the bleed port will only help get you out of a jam if you stall in a bad spot. That should not happen to you. Put a clear hose on before the Mega and look to see what's going through there. It will be worth the 15 minutes. Also, if this continues, maybe we can meet to troubleshoot and work on it. Houston is a ways south, but I don't want to leave you hanging and stalling and I have to see it to help fix it.
All,
I should clarify that my auto bleeder is only automatic from the point it will allow me to push a button to bleed rather than pump the primer pump. I guess I should really call it a purge pump or bleeder pump instead of an auto bleeder. I, like JK, have never had a problem with stalling either before or after the Mega install. I did have air before the install and I still do. My question is How much and do you get to a point that you push the air through the Mega just like any other filter. A post air trap will answer that question and I have the parts. Some people don't have any functional problems before or after (like me), others do (like Houston). The comment on additional Vacuum to the system has merrit. Now, I started with 3-3.5" Hg before the Mega and ended with 4-4.5" Hg after it was in line. That's not much of an increase, but if you were marginal and had a leaky system before, I can see how that would make your problem worse. The question is, for the poeple that have the no start condition, does filter age matter? If yes, then the vacuum increase might be a cause. If no, then a leak somewhere high on the system is probably your best bet. There has been no proof that the Mega filter is causing air in the system, only that it traps it. If you do not think air is bad, that's your choice. If I have to push a button for 10-20 seconds every 3 or 4 days (TBD with trap) to bleed the air that the mega has trapped, that's okay with me considering the alternative. I don't think I will "HAVE" to, but may "Want" to. I need some time to eliminate the other areas that might be leaking in my system. Just about everywhere you have a fitting or hose is a candidate. The OEM clamps and QDs are junk. Don't believe, put on that clear hose.
Dave Lewis
05-08-2003, 19:20
56Nomad,
I don't think the air is going to damage the injectors or the engine. I do however know from experience that air will damage pumps. Whether there is enough air in our system to cause damage to our pumps remains to be seen. I for one would rather remove whatever I can than take my chances on a failure later on. Some people may run their trucks for 10 years with no problems, some maybe only 1. I want to be in the 10 year group, plus I enjoy doing it. Just my thoughts. Take a look at this and it will show you what air can do to a pump.
http://www.proactivefluidpower.com/support_plate_failures.htm
Lone Eagle
05-08-2003, 19:21
Hoot & 56Nomad. Where did you put the air bleed on your Racor? Later! Lone Eagle
Yup sure is a odd application ....
=> Descriptions : High-Efficiency Microlite Fuel/Water Separator Spin-on with Drain
Contains : Integral Post Seal
Fits : Mining Applications in Cold Weather
Thread : 1 3/8-16
O.D. : 5 3/8 (136.5)
Length : 10 9/16 (268.3)
I.Gskt : [1] Included
Not sure if it means anything ... Cause I don't know what Diesel it's used on or could be ,yet .... Cat ??
MAC
Look in my signature.
Fuel filter pics.
It's a standard brass petcock. We put it on top, where it should be. Accessable by pulling the headlight.
Bleed once, drive till change time, replace filter, repeat.
[ 05-08-2003: Message edited by: hoot ]</p>
GMC-2002-Dmax
05-08-2003, 21:00
Hey everyone.
Air does not care what path it takes to get out right :confused: .
Anyway, if most people, not all are getting air use hoots method, again but use hose to remotely mount the bleeder in the engine compartment where it is really easy to get to.
I am waiting for some more info before I make the mod myself. Just thinking out loud.
hoot, you got mail.
GMC ;)
Lone Eagle,
I used a brass petcock that I purchased at
Orchard Supply Hardware for my bleeder.
Photo of the installed petcock at:
http://community.webshots.com/photo/66562661/66614167KPhgHm
I can access it by removing the headlight assembly,
however, the only time I need to use my bleeder is when
I change out my filters. Then I take my plastic inner
fender shield off to do that as shown in my intall
photos.
[ 05-08-2003: Message edited by: 56Nomad ]</p>
Dave,
Thanks for posting the link to the pump failure pictures
LanduytG
05-09-2003, 05:14
Well I can't stay out of this any longer. Some have air and some don't. Now lets look at this, look at how the ones without air have installed the filter along with how the lines are run. Duplicate it on the ones that have air. With the location of the filter it is acting like a P trap. MEaning you have fuel going up to the OEM filter then back down and then back up. This is a P trp which will trap the air and not let it move. Yes the fuel systems has air leaks and it shouldn't but the OEM does not trap this air and if you install another filter on the frame it does not trap air and lone eagles filter up high does not trap air. So just move the dam filter and get it out of the P trap mode.
Another thing is the filter itself leaking air. Hand tight is not good enough. While I was develvoping a fuel filter to replace the OEM filter in the VW TDI I found the the Cat filter has very hard rubber for the seal. While I had the filter together on the bench I put the mighty vac on the setup. I would pump up 25" of vacuum and it would leak of at a rate I did not like. I looked all over the thing and could not find a leak. Finally I thought I would try to tighten the filter up some more. It was already tightened to a point of one turn past the contact point. I took it 1 more turn and the leak stopped. Now I have not seen the Baldwin filter so I don't know how hard the seal is. The Racor is softer than the Cat and getting it top seal is easy. This is just food for thought and some trouble that I have had in fuel filters.
Greg
HoustonDMax
05-09-2003, 06:04
One thing I had not tried was tightening the filter further, as Greg suggests. I will do that right before I leave for the weekend shortly.
Wouldn't a P trap trap fluid, with air trying to get to the highest spot. That is why, at least to my thinking, that the air is being trapped in the top two inches of John's design. The nipple extending down from the base leaves a two inch dead space for the air to accumulate. The other designs do not have near this volume left on top, as I understand it.
I agree that the best thing is to find the source of the air. Until I can track that down, I want to have some means to release the air that I am trapping without wearing out the oem primer bulb.
I think I will have access to the internet where we are headed this weekend, so Chris, I will give you a hollar to talk further.
Thanks for everyone's input so far.
HoustonDMax
chuntag95
05-09-2003, 08:41
Greg,
I don't agree with the p-trap theory completely, but location and line routing is somthing to consider. How you route the line can cause areas that air will be trapped. Case in point is the EDU. I can pump the primer and see bubbles in the top of it at any time. I hope my additional pump can pull some of that out.
Houston,
I here for you buddy. If you want, shoot me an email and I can send you my number so we can talk. We are having a get together up hear next weekend on Saturday if you want to come up and meet a bunch of other DMAX folks.
All,
My plan for the weekend is to add an air trap post Mega to see if air does go through it at some equilibrium state as Bill pointed out. I believe that is the case for the folks that don't have any problems not bleeding in an eternity. People with a no start problem have a leak IMHO. I am also adding a larger air trap pre Mega that I can get an idea of the volume. Finally, I am adding a pump to use to manually bleed the system without using the factory hand primer pump. Can anyone suggest anything else I should do while I am tearing my truck apart. This is how Frankenstein got started I bet. tongue.gif IT IS ALIVE! :eek: :D
This Just Came To Me...............
For those who bleed their Mega Filter and never have gas, I find this peculiar. Is it possible that these individuals have plumbed their Mega Filters backwards? This is a very easy mistake to make. If the fuel in your Mega Filter is flowing the opposite direction because it is plumbed backwards, you would NEVER trap air in your Mega unit. Anyone with NO air please reply and verify a correct installation. SPICER tongue.gif
Felpa,
If you are not finding air that is great! Hopefully it will remain that way.
I have a FAQ page in the works and hope to have it up soon. This should help answer most questions...
Good point Arlen! Later units are engraved to help clarify...
Greg also has a good point about the sealing of the filter. Of course, if the air is aleady present at the EDU...
I have a suction nipple w/o the extension for the post seal if someone would like to try it...
[ 05-09-2003: Message edited by: kennedy ]</p>
george morrison
05-09-2003, 10:52
Confirming Greg's excellent suggestion of filter tightening. We are all so attuned to oil filters rule number one of NOT over-tightening the oil filter due to it being impossible to get off, that we need to re-learn procedures with fuel filters. My experience has been that I have had to really crank on the filter for good sealing/seating, completely contrary to years of oil filter replacement..
George
While the filter to mount seal MAY be in need of attention, and I'll remind people that we are dealin with vacuum and not pressure which requires even better sealing, the fact is that most have observed air BEFORE the filter system.
In order to save band width, here is a link to a "quickee" FAQ page that I whipped up:
http://www.kennedydiesel.com/docs/Duramx_Mage_filter_FAQ/duramax_Mega_Filter_FAQ.htm
Now I have to go finish putting my turbo back on...
Mark Bajus
05-09-2003, 13:10
best link on the Ford cackle stuff is this one- it used to be direct but now you have to register- no charge as far as I know. This guy spent TONS of time/money working on it: cumbustion process analysis ect ect.
http://www.texastowncar.com/
one of the first attributes a "cured of cackle" ford gained was increased fuel mileage...much of the air was coming from poor tank design, poor fuel line fittings.
chuntag95
05-09-2003, 13:37
Has anyone who replaced there tank with one of the aftermarket ones seen air?
When fuel in the tank splashes it folds air into itself. Just like shaking a jar of fuel. I don't think return fuel issues will really make a huge, if any, difference.
I truly believe that normal entrained air gets handled more than adequately by the hp pump. Once the fuel is compressed, problem is gone. I don't think the air comes out of solution until it's in the cylinder.
What we do not want to do is collect air and send it through in gulps. You guys that are having stalling issues better watch out.
[ 05-09-2003: Message edited by: hoot ]</p>
Mark Bajus
05-09-2003, 13:49
just logged onto texastowncar's ford cackle website. Its free, tons of info. Paraphrasing from his site:
as low as 3% air in fuel shortened life of injectors.
fuel pickup assembly IN THE TANK replaced as it introduces air
fuel line from tank to pump replaced as it introduced air (poor connections...)
You guys have to be careful when comparing the Powerstroke to HPCR engines. The Powerstroke injection system is a totally different animal. It doesn't have fuel pressurized until it reaches the injector, a lot like conventional injection. That means there is a much greater chance of aeriated fuel immediately entering the point of injection and related parts. I do not believe fuel at 20,000+ psi, built up at the hp pump in the Dmax system will have air in it that will cause problems.
In the DMax, first the fuel is pressurized to injection pressure way before the injectors. You have the injector lines and the rails fully pressurized. I think if we could analyze the fuel inside there, we would get a better picture of how the fuel is absorbing the air. I'm sure this is basic fluid dynamics that some engineers around here would know about.
[ 05-09-2003: Message edited by: hoot ]</p>
http://www.kennedydiesel.com/docs/Duramx_Mage_filter_FAQ/duramax_Mega_Filter_FAQ.htm
John,
Thanks..... you covered all the bases.
Fuel splashing around will not put more air into solution due to the fuel already residing at max saturation levels for the given temp and pressure. Air bubbles from splash would only be a problem if it is sucked up immediately before separating. It takes pressure along with time/air source to saturate the fuel further. The design of the sending unit should prevent splash from readily getting into the suction unless someone drives their truck in a manner in which it won't last long anyway. The return fuel however which goes through the pressure drop needed to flash out vapors returns right to the sender cup about 1" from the suction. In a better explanation look what comes out of the nozzle after the pressure drop when you fill up. Should know in a couple of days if this is a contributing factor or not.
I've actually got a schematic based on the GM provided one, only with a few items relocated to better represent the underhood layout. I plan to put this in with the Mega instructions so that those who want express instructions can see what we are doing...
LanduytG
05-09-2003, 18:56
"I don't agree with the p-trap theory completely, but location and line routing is somthing to consider."
Once the filter traps the air it will not move out. Then you have a p-trap. I bet if you were to move the filter up so it is the highest point in the fuel system the air trap problem goes away.
The best way to illustrate this is to attach some fuel line that you can see through. The VW TDI has this. Start to move the line around and form a big p-trap and you will see the p holds air. Fuel will pass through it but the p still holds air. Now in the case of the fuilter itself as the air displaces the fuel you end up staving the engine.
But I would first check to see how tight the filter is. Nature hates a vacuum.
Greg
chuntag95
05-09-2003, 19:49
Just a quick note. The pump (8012) will self prime. It pumped a bunch of air before it pulled in the fuel. Good call to he who specified it. Install is not complete, but well on it's way.
Lone Eagle
05-09-2003, 20:30
Greg, I bet you could get it out at the First Start Bleed Port. Later! Lone Eagle
chuntag95
05-09-2003, 21:25
Greg,
I am just not on the same page with you, but I am trying to understand. I respect your opinion and knowledge and mean none of this in a negative way towards you. I am just trying to get my brain around this.
From my thinking, regardless of where you put the Mega filter, it will trap air due to it's design. Regardless of where you put a Racor or Stanadyne, they will not, unless they are at a high point in the system, again due to design. People have put a Racor in the exact same place as JK's Mega without traping air (Hoot, speak up here). The traping is a function of the filter head, not the location when talking about the Mega. You can get some air traped in different parts of the line or system, like the EDU. It always has air in it. I have a clear line there and can see it. The high spots will trap the air, not the low. Right now, the only thing lower than my Mega is the line to the tank. Everything else is higher up. Assuming air always moves to the highest point, then the air should get trapped in the EDU and OEM filter or the line existing the Mega filter head going to the top of the engine. The problem is the air is moving down from the OEM filter to the Mega because of the flow pulling the air along. It cannot go any further until the top 2 inches of the Mega are full of air. At this point, the air will slowly move out as it moves in or you will lose suction and get not fuel. I am not exactly sure which, but am working to answer that question with my experiments.
Keep trying to straighten me out here, because I really want this fixed. smile.gif
Here is the fix...
Remove the Mega filter.
Chris, Exactly
The air can collect at any up dip in the system provided there is not enough fluid velocity to carry it to the next high spot. The filters will function as designed (to trap or not to trap) no matter where they are mounted. PERIOD
Just another thought..... Since it is essential that the fuel
filters be screwed on very tight in order to avoid air entry
into our systems, I have a question for the experts.
Looking at photos of John's filter head, the Mega filter gasket
engages with a flat smooth machined surface. I'll assume the
ring gasket is round as with our OEM filters.
Could it be that this rounded gasket might function better
if the filter head had a machined groove to seat the gasket into.
A round gasket seated on a smooth flat metal surface would
seem to be able to allow air in under the vacuum in our fuel
lines. Could this be the source of air with some of the
Mega folks?
Kinda like Tupperware............ It's easier to burb than
allow air in :D :D :D
[ 05-10-2003: Message edited by: 56Nomad ]</p>
Bulldogger
05-10-2003, 13:10
Just a thought, what would happen if you shorten the nipple depth on the mega filter to match that of a Racor or Stanadyne. It shouldn't effect filtering quality and since the other style filters mentioned above allow air to pass without ill effects would you end up not having to bleed the system? John did you try this yet? If not make one and send it to me and I'll run it for a while. Dave
HoustonDMax
05-12-2003, 06:01
No computer access this weekend, so I am just now getting back to this.
JK, I will take you up on the shorter nipple offer, if someone has not beat me to it. This will only be interim, as I want to find the source of my air intrusion. Send it to me, usual address, if you still have it.
Road trip results. No stall for in excess of 250 miles, including 45 minute lunch break, and rest stop stops. End of trip, both ways, stall, after truck sits for extended period. Bleed till fuel comes out, stall again. I then have to add another round of priming with no bleeder open, and then she stays running.
My next course of action was going to be taking the Mega filter out of the loop, while I either track down the air source or install a set up that will allow me to monitor air volume and bleed without wearing out the primer. JK's short nipple would allow me to leave the Mega in series, and still track down the source. No matter what, I need to find the air source.
Thanks for everyone's input.
Just got back at 2:00 am.
After going 150 miles truck sat for 6 hours and started then died.Pumped 20 times and she starts right up.
Same thing happened when I drove to Seattle on thursday.
Went and got a bite to eat came out and it started and died in the parking lot.
Pumped 10 or 15 times and all was fine.
Leave truck at park and fly(1 mile away) and she starts right up 3 days later when we got back.
Hope this makes sense as I'm a little foggy with not much sleep!
chuntag95
05-12-2003, 12:07
NWDmax,
So if you drive for a long distance, you get a stall, but if you go for a short trip (1 mile) you don't have a problem? Sounds like you need time at speed to draw in enough air to lose prime.
Houston,
Will send nipple ASAP for exp. purposes.
Just to clarify, I am under the impression that the only time anybody stalls is immediately after startup, as in once underway, it is fine and so lonag as it is not shut down it will not stall?
SoCalDMAX
05-12-2003, 13:15
I would have to agree that the air seen in the filter is NOT an artifact of the filter itself. It is merely showing up there because of the 2" nipple allowing a place for it to get trapped.
The only way for the people with an "air problem" to find out where it's coming from is to experiment around and try replacing QD fittings with fuel hose and clamps, try tightening the filter element a little more, etc. It's gonna take some time and step by step documentation of what you did and how much change occurred.
The actual source of the air may be different for each of you. The correct answer may be to eliminate all possible sources of vacuum leaks. This is what the Ford guys discovered months ago. I haven't read any of the more recent threads over there.
Hoot, I don't agree with your assessment that the air is not a problem with the Dmax. Whenever a fluid goes through a pressure change (as slight as a propeller going through the water) entrained air can/will be released. Picture a propeller on a sub. Shrouding the screw drastically reduces cavitation. So does polishing the blades. So does increased depth (pressure).
IRT our fuel pumps, the cavitation occurs at the impeller surfaces, and as one of our experts pointed out, the violent explosions of the air (gases) coming out of solution suck the finish off of the metal and can cause severe pitting. This could be tearing up the pump. IMHO, the pressure on the outlet side of the pump is the same as the pressure differential on the backside of the impeller.
Let's assume that the pump is "remixing" some air back into the fuel. Now we have a pressurized fuel rail that was designed to carry 100% fuel - designed and tested on a test stand that was probably fed by a 100 gal. holding tank with gravity feed.
Now the air that is entrained in our fuel rails is compressible, so the injectors aren't giving a full shot, or a delayed shot. This has to be affecting power and economy. Anybody with a chip can attest to the power gains from advancing the injector pulse.
I agree with you that the Ford fuel system is more susceptible and sensitive to air bubbles and entrained air, but I believe it affects us to a lesser extent. I've asked myself this question: "we've all been told by some Cummins owners that they've gotten 22,24 maybe even 25mpg. are all of these older Cummins owners lying, or is there something fundamentally different in our injection systems that's causing a more advanced diesel to get as low as 13mpg. Looking at the results Texastowncar got (14-15mpg on PSDs with air leaks, 18-20mpg after removing the source of the leaks), I'm wondering if air isn't the source of the problem.
This would explain why we're seeing differences in Dmax mileage - those with the worst leaks are getting the worst mileage, those with good sealing on their fittings are getting closer to 20mpg.
Regards, Steve
I think a big and heavy right foot has a lot to do with mine 14 to 16 mpg avg mixed.......how ever on friday I made a 146 mile trip with the cruise set on 65 to 68(lots of cops and curves) filled up to the top of the neck before and after........6.6 gallons........gofigure.....22+.........Normally I couldnt get that with mine on a roll back..........didnt suck much air that day. Im lucky enough to have my own 1000 gallon tank and I have installed a nice pre filter to the nozzle after the pump not sure how many microns but Its got to help.............I regards to the air it looks like it is getting time to find a suitable lift pump............ :D dave........hey steve how many mexican beers does it take to make a so.cal. guy stagger :D :D :D ?
Steve.
I agree with much of your post but you are making assumptions about testing and you are comparing a screw to a piston pump.
The Dmax injection pump is a radial piston pump. There is a location in the pump where fuel pressure goes from a vacuum to 20,000+ psi. This is where air that is already "sucked out" of solution gets instantly compressed. That is not where cavitaion occurs. Cavitation occurs in the opposite situation, when bubbles are released, not compressed. No explosions here.
I also don't think Bosch would have left out GM's fuel suction design when spec's and recommendations were initially shared. I doubt if Bosch and GM did not understand what is happening in the fuel path with respect to air.
And finally, couldn't we simply add a fuel pump back at the tank and reduce the vacuum? The reason I say reduce is unless the pump is strong enough to push through both filters, you'll still get some "pull" in front of them.
SoCalDMAX
05-12-2003, 18:59
Hoot,
OK, so if it's a radial piston pump (isn't there a 3 vane rotor in there somewhere, or is it a 3 piston pump?), then on the intake stroke, the pressure drop is when the cavitation probably occurs. According to Doc Dyno, our fuel systems expert (I wonder where he is these days?) just having a rough edge on a fuel fitting is enough to cause cavitation in the fuel line.
It's the differential pressure between the inlet and the outlet that I believe could be causing cavitation. We aren't going to be able to eliminate the cavitation caused by the fuel pump itself, but perhaps if we install a lift pump at the tank and put a slight pressure on the fuel filter(s), it might help keep the air volume down.
On a sub, there is a high volume pump on the trim and drain system. There is also a priming pump on the system, to maintain proper suction for the main pump. I guess this is the concept that keeps making me think a lift pump would help immensely. One of these days I've gotta stop sounding like a broken record and find the time to install this stuff and make some measurements, take some pics. ;)
Regards, Steve
I believe the Cummins guys are putting the Fuel Econo numbers together buy getting the job done at a lesser RPM consistently .... Those I 6's aren't revers like a V8 ....
MAC ;)
Lone Eagle
05-12-2003, 19:39
SoCalDMAX, Check out this past thread. I gave a texbook definition of cavitation, airation etc.
My post is almost at the bottom of the page. Later! Lone Eagle
http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=005544&p=
Here is a description of the pump.......
The Bosch HPCR pump consists of a three element radial pump driven at camshaft speed.
The elements (plungers and barrels) are spaced at 120 deg intervals and the cam that drives the plungers has a mild profile so the load on the drive gear is almost constant compared to the load spikes normally associated with inline or rotary pump drives.The inlet and outlet of each pumping element is controlled with simple (but also very precise)check valves and the outlets are all channeled together in the pump body before reaching the rail connection. Rail pressure is controlled by throttling fuel at the inlet side of the pump, using a pulse-width modulated solenoid valve. The valve only needs to work against fuel pressure generated by the gear type feed pump, which is limited to about 20 psi. The feed pump is mounted on the back of the high pressure pump and run by the same drive. The Rail Pressure Control Valve (RPCV)is mounted on the main pump body. Power needed to drive this pump is extremely low.
Maybe somebody can use some of this info in their experiments.
[ 05-12-2003: Message edited by: hoot ]</p>
Lone Eagle
05-12-2003, 22:15
Two stage pump. Interesting! I don't suppose you have a drawling do you Hoot? How many pistons on the HP pump? Later! Lone Eagle
HoustonDMax
05-13-2003, 05:58
John, thanks. Will keep everyone posted. I fully expect that to eliminate my stall problem. Still leaves me with the air intrusion issue, that I must track down. Once I think I have that whipped, I can put the long nipple back on to verify.
My in town mileage 15 to 17 seems to be right where everyone elses is. My highway mileage never gets above 18, which I would expect better considering my in town mileage.
Only stall I get is right after start, and occassionally a no start after sitting overnight. Never had a stall once up and moving. If so, the filter would have come off immediately.
JK:Longer drives always seem to end with a no start after shutting down for a short period of time.
Should get the clear hose installed today between the FICM and Stock fuel filter inlet.
I'll report back my findings later.
Chris: I believe you are right on.
Lone Eagle
05-13-2003, 12:39
Thanks a bunch Hoot. Good info. Later! Lone Eagle
Houston -
Did you install the short nipple JK sent you, and are you able to share your findings with us? I hope you got a winner!
Not that I want to push you, but there are a lot of folks out there with the "bubbly".
HoustonDMax
05-20-2003, 11:58
Posted update under Clear Bleeder Line Installed and This is What I Found thread; details there.
Summary, yes, installed. To early for conclusion, but promising so far.
Houston -
Thanks for the info! Will be looking for your progress report. You are on the cutting edge of filter technology!
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