Fixing the air leak

[Bulldogger]

I know alot of the members are addressing how they are going to deal with the air leaks with injector pumps and auto bleed valves, but how about some help for those of us who just want to fix the problem. After replacing all quick disconnects on fuel lines, What have been the results? Where are other possible sources for the air leaks? I personally want to make the system air tight without adding any check valves or pressure pumps. How about some help for people like me. I can't be the only one who just wants a simple fix. A Bear you replaced most of the quick disconnects on the fuel line. What were the results and what is the next step? Thanks, Dave :confused: :confused:

[56Nomad]

Bulldogger,

Do you have the Mega Filter installed? If not, what secondary
fuel filtration do you have?

[ 05-08-2003: Message edited by: 56Nomad ]</p>

[Bulldogger]

56 nomad, I'm running the JK set-up. Its trapping air no stalling problems but I bleed it every 300 miles. Interesting part is the OE filter leaks fuel on the first pump, even though it takes about 50-60 to clear the mega of air. Dave

[jbplock]

Dave,
You may not have any external leaks. You also might want to just try running with out bleeding and see if you experience a no-start. As long as the fuel level in the mega doen't drop below the clean side nipple the system will stay primed. After I play around with the bleeder idea this weekend, I plan to just keep running with out bleeding and see if I experience a problem. From the testing I've done on my truck I don't think I have any external leaks.
smile.gif

[ 05-08-2003: Message edited by: jbplock ]</p>

[Bulldogger]

Jpblock, I been running 300 miles at a clip and bleed out air every time. I think that if I just keep going eventually it will catch so much air it will stall. I really only tow with the truck and I don't want to get caught stalling with the 5th wheel. What bothers me is some people have no air problem while others have more extreme air problems. Other then replacing all quick disconnects and factory hose clamps where are the other possibe air leak sources. I may just take the truck to my friends shop and pressurize segments of the fuel system to see what I can find. If air is getting sucked in then there must be a way out. Dave

[jbplock]

Dave,
I relate to not wanting to get stuck with the 5th wheel (I had a 30 footer that I used to tow with my 98). As you said, doing the tests is the only way to know for sure if you have leaks and the places you mentioned are where they would be. But, assuming there are no leaks, the MegaFIlter may come to air equilibrium and just pass the excess air as the filters with out the long nipple do. I haven't given mine a chance to work long term because I have been worried about loosing prime (I bleed every 300 miles too). So, after I tinker with the pump bleeder, I'm just going to run it until something happens - if at all. The results of the long term run, will determine my next step(s) (i.e. Verify no leaks (again), auto bleeder or pressurized system, etc.)

Also, if you haven't done so already, checkout Tommy's latest test results.

http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic&f=3&t=005741&p=2

He has proven that his system has no leaks under pressure and vacuum. Can't wait to see if he still has gas.
smile.gif

[Cowboy_120]

Ok, maybe Im a little slow, but I am running my truck stock, and I havent had any problems with air in my fuel lines. Why is this such a major issue? Have you guys done something to your trucks to cause it? ( I am not pointing fingers, I mean anything like running the juice or other mods?). If it is such a problem, why hasnt GM put out a recall to fix the quick disconnects?

I am just a little confused.

[OC_DMAX]

I have been following these fuel filter posts for quite a while now (probably like 1000 other people). Learning new things everyday! A comment or two,

First, there is a very similar effort taking place on "TheDieselStop.com" Ford website. I believe this has been mentioned previously. About the same time people started worrying about fuel cleanliness here (around October), George Morrison was also raising the issue on the Ford website. Similar tests were run. The difference being the Ford OEM fuel filter is sufficient (actually a Racor product too). A number of people are adding a primary filter/water separator (Dahl 30mic) to their Ford diesels. They have run into exactly the same problems you have here. Air in the added fuel filter. There are at least three very large threads over on that site dealing with fuel cleanliness, quick disconnects, fuel tanks and air in fuel. Many similar activities taking place. For those experimenting here, maybe some conversation with individuals on the other website would be of use. It always helps exchanging ideas and sharing lessons learned. If nothing else, read the differenc threads. Just a thought. Referenece the following as an example:

http://forums.thedieselstop.com/ubbthreads/showflat.php?Cat=&Board=UBB33&Number=1089017&page=1&view=collapsed&sb=5&o=&fpart=1

(If link does not work, look in the 7.3 liter engine forum, search back through Oct 2002)

Another article of interest is the following:

http://filtercouncil.org/techdata/tsbs/94-6R.html

This may explain why there is some air on the dirty side of your super duper Mega Filter. Maybe its not a bad thing for the filter to be partial filled with fuel and have a little on the dirty side of the filter ? (as long as a steady state situation is reached)

Just some thoughts.

[a bear]

Buldogger,
Your OE filter bleeds fuel right away because it won't trap any volume of air by design, where as the Mega filter has a void between the bleeder and the nipple extension. I did have a leak at the quick disconnect by the tank but also changed the one above the drivers side valve cover. Repairing these with hose and clamps got rid of the no start and the majority of the air but a little remained. I have concluded by testing the entire system that the small volume that remains is probably outgassing. I am presently taking my fuel return to the tank fill to see if any air is mixing and being picked up in the sender unit. I will run a couple hundred miles like this and recheck for air. I will post the results. smile.gif

[Bulldogger]

Bill, thanks I never even considered it reaching an air equilibrium, excellent point because the racor filters do pass the air do to the lack of the 2" nipple that is on the mega. Cowboy, the factory filter never caught any air. After 3500 miles I cracked it only to have fuel seep out and no air, trapped air is unrealted to any mod that was added, it has to be present in the system prior before it can be caught. DC Dmax, I'm not a member over on the other board but have read postings, and it seems to me that when somebody posts over there to ask a question that doesn't own a ford,that your a troll or trouble maker. Very few members have been helpful from my past readings to others that have posted like Motomac or similar name. To me I drive what I like and consider the maker of less importance. Dave