fuel filter

[jlog]

i have been lurking on the dmax site following their discussion about additional fuel filteration. They are reporting increased milage with the addition of 2 micron filter set-ups. Have any of the 6.5 operators considered or tested this add-on filtering. The main reason for the filters is extending the life of their injectors and pumps.
John

[damork]

I've added a 30 micron pre-lift pump Racor model 645 to my truck and am considering a 2 micron to replace the 5 micron stock filter on my 6.5. All 6.5 factory filters are 5 micron, made by Stanadyne. I contacted Stanadyne and although they think it is a good idea, they don't offer a drop in replacement.

FWIW - Caterpillar has changed their secondary fuel system filtration to 2 micron on most or all new electronic diesels as the newer systems are not as contaminant tolerant as one would wish. I don't believe adding a 2 micron secondary to the 6.5 would harm anything - seems like a winning idea. For cold weather, buy the heater that comes with the filter or use #1 fuel when it is cold.

[CareyWeber]

damork,

I have a Racor 445 w' a heater before my lift-pump. I've thought of adding a Racor 2 micron filter to replace the factory filter, but could it be wired to use the same dash lights?

One good thing would be moving it to an easier to reach location.

Carey

[ 07-29-2003, 06:28 AM: Message edited by: CareyWeber ]

[damork]

CareyWeber
You are thinking the same thing I am, but I don't see why it wouldn't work. It is probably going to be later this fall before I move to the Racor 2 micron secondary.

I think the same power that feeds the fuel heater on the oem unit could either power the Racor directly or through a relay (not sure of the power required by the oem heater, I think the Racor is 200W).

The water sensor circuit should operate the same, but I am looking through my schematics to see if there are any differences. I've been looking at the firewall for an alternate location to mount the Racor. Seems moving the oem filter would add a little airflow under the intake too. Adding bleed valve on the top of the Racor seems to make sense as well.

[MikeC]

Sounds like the start of an article! :D

Mike

[tom.mcinerney]

I removed my OEM conditioner from IM , installed it and a second OEM assembly along frame out of engine compartment. I have one before and after the lift pump; if no 'water in fuel' light before fuel up and two after i know i've picked up > a pint of water.
Relevant notes: My Helm manual states the fuel heater activates at about 45* F, well above the point when waxing is an issue. I'm pretty sure the manual says it's a 100 watt heater. I checked out two heater assemblies. They both turned ON in the refrigerator(about 40*F). More important, the activation showed hysterisis--one turned off only at about room temperature. The second stayed on overnight, temps >80*F.[So they won't cycle endlessly--the Stanadyne OEM sensor is a bimetallic spring-disc, with a contact point attached]. If the heater stays on until 80*F is reached(probably makes life easy for FIP), it might be just as well to leave in engine compartment.
While the heater incorporates an electromechanical switch, not so the OEM water sensor. These {i THINK} monitor resistance between metallic button protruding into fuel and ground. There appear to be two circuit components in addition to the resistance sensor: 1.) A time delay of 6-12 seconds-possibly more for the first 'on' , 2.) a gradual 'turn-on'. These need to have the low point of the fuel in contact with a grounded conductor. I found the sensor would illuminate a 'clearance' bulb directly connected per Helm diagram.
High mile heaters can fail. My heater element burst explosively, and the sense/switch assembly was also burnt. I think the older models can leak a little (allowing a little air in?).
Two questions:
On later vehicles('96-up), is there a spring spacing the heater from its surrounding tube(and forcing the fuel to spiral in contact with heater)?
If you want to replace a spent OEM heater , can we buy one from Stanadyne for their conditioner assemblies which will fit? What part number?

[slagona]

Peninsular Diesel used to have complete assemblies (take-offs) available - probably can get the whole thing cheaper than just the heating element. They don't list them on their website, but you can give them a call and see what they have. I used to get enitre assemblies from them just because they were cheaper than a filter alone.....

[jspringator]

What would happen if you used a 2 micron before the lift pump?

[damork]

James,
A 2 micron filter might work, but it is not typically installed in a suction line. Problems will show up especially when it gets colder and the waxes start to plug the element. You are better off with a 30 pre-lift and the 2 micron in the pressurized side of the lift pump.

There has also been some concern over the use of a 2 micron in cold weather, but filters come with heaters and even the use of blended or #1 fuel helps you make it through the winter. I believe 2 micron elements are going to be more common as people and manufacturers realize the benefits.

Dave

[jspringator]

I currently have the 30 micron before the lift pump. Mine has a heater. I was hoping that the heater may let me use the 2 micron in the pre-lift pump filter. That would save money on having to buy a new filter, and make filter changing easier. I have a bypass valve plumbed in if reduces flow.

[Turbine Doc]

If you go to Racors web site they describe a 2 micron filter for final filtration and 30 micron for primary, in some case a 10 for primary if raw fuel quality is presumed clean. A lot of heated debate on the DMAX side on issue of filtration.

Here is my opinion no scientific data to back up my assumptions for what works in truck fuel systems but just some real world observations on ship filtration systems for fuel to the propulsion and power generation jets burning marine diesel.

Which is super refined #2 diesel, not JP-5 or 4 which is a kerosine derivative(that is the emergency fuel supply on hand) but too expensive to run always at 132gpm for 4 25KHP propulsion turbines full speed 100K propeller shaft HP, 2 generators 5000KW electrical load.

In those systems sailors rather than change the blocked filter, would pull the power fuse to reset the alarm, eventually the alarm would stop coming on. This was because eventually with enough pressure surges on the blocked element a hole would get blown in it and element was then functioning in bypass mode, raw unfiltered fuel going to the fuel metering valve and injectors.

A super fine filter catches every thing & once plugged if not changed, will eventually get a a hole blown in it and that filter media now becomes a contaminant in the fuel system; so a plugged 2 micron primary once plugged blows and provides no filtration plus it too adds to the available junk as it disintegrates from within.

We have found many jet engine controls with filter media cellulose in places where it should not be, took a lot of time to determine cause, once junk was identified we knew the failure mode was found by watching action of sailors on watch not wanting to drain 100 gal fuel resivor and 10 fuel soaked filter towers, taking avg. 6 hrs to complete task.

Now I use the term blown hole loosely 2 micron is small , you would be hard pressed to "see a hole" in a 2 micron filter element.

Ship systems use a coarse filter to knock out chunks if you will, then fine filtration for finer stuff. A 2 micron filt will plug faster than a 30 micron so intent is to knock out biggest junk 1st still maintain flow with the 30 micron then only thing to final filt is <30 micron. I would venture to say in most fuel there isn't a lot of <30 micron stuff to be caught.

My set up will soon be 30 micron to pump to 5 micron stock filt with differential pressure switch on each to let me know when filters are blocked, so I can change when needed rather than arbitrary mileage. If you get a bad load of fuel on the road plugging filt you won't know you have a problem unless performance suffers or in worst case after a filter fails because plugged and blows a hole sending raw unfiltered fuel to the IP and injectors.

Just my opinion and logic do with it what you will, and do what you think is right for you, I don't want to start the storm of controvery they had on the 6.6 same issue.

[David Brady]

I have recently mounted a CAT filter post the relocated factory filter to help extend the life of my injection pump. I am planning to put a gauge on the outlet but haven't yet. I have seen no increase in mpg, and I really didn't expect to. I have been averaging 20 with mostly freeway miles at or +5 the limit.

[ucdavis]

Coupla random thoughts:
1) When this topic came up maybe 6-9 months ago, it was mentioned that Stanadyne recommends against 2 micron filter, due to loss of pressure feeding IP.
2) Recent posts on 2 lift pump configuration (in line) were showing 11-13 psi @ IP vs 4-6 spec for single LP at idle. W/ fuel demand @ WOT, I'd expect a 4-6psi single LP would drop to near zero positive pressure or maybe a tad negative. These figures were, I believe, w/OEM filter setups. This would square w/Stanadyne's squeemishness over additional pressure drop by greater filter drag.
My opinions:
a) 2 micron filter is a good idea, but requires xtra lift pump capacity to assure IP has adequate lubrication & isn't under added stress having to pull it's lube supply,
b) The idea of pressure differential switches is a great one for not having to guess at filter activity.
Tim- do you have part numbers & suppliers for your intended differential switch assemblies you could post?

[Turbine Doc]

In my own experience single fuel pump 5 micron fact filt stomp on accelerator from 40mph and fuel bowl drain with gauge on it goes from 4 psi to 2 psi empty truck no load no problem, put on head of even finer filt 2 micron and I'm sure you make extra work for the inj. pump or added load, or dirty filter had a bout of "fishbiting" earlier due to dirty filter, fixed with new filter.

Sunday I pulled rough estimate 10-12K of trailer, tractor, bush hog,& disc gang. No problems other than up long grade max speed was 60 mph, 2000 rpm max engine speed, going flat no problem pulling 75mph I can't remember for sure 2300 rpm only did it once (I did not like that much speed with that load), plenty of EGT left max I ever saw was 800 once, avg was 650-700 post turbo. Basic problem I think was lack of fuel just not enough delivery to IP single pump.

Racor has switches, any Racor dealer can get them I think, I've got my notes at work home for lunch checking in. Look under their 300 series filters spec sheet and you will find a vacuum switch set for 7" to alarm the blocked filters for the 300 series filts, vaccum is vaccum so I'll just adapt as needed have the switch drive a 12v LED to let me know I'm at alarm condition. When I get back I'll post PN's and where I'm buying them.

[ 09-30-2003, 11:05 AM: Message edited by: tbogemirep ]

[Turbine Doc]

UC sorry about the delay, had to take a ship to sea for testing before delivery to the USN.

PN for the switch is RK 20163 connector is
RK 21030

check out www.parker.com/racor (http://www.parker.com/racor) or call 800-344-3286 06:00-17:00 PST good bunch of folks tech dept answered most of my questoins I could not find info on at their web site

[BuffaloGuy]

Here's another thought.

Yes, the modern diesels, like the durmax, benefit/need 2 micron filtration but the 6.5 is 20 year old technology. The new diesels have fuel pressures that are unbelievably high and as such the tolerances are much tighter. So it would follow that the fuel needs to be filtered much better.

The 6.5, however, is like an old 1911 colt .45. It was made to be dropped in the mud and still be able to fire reliably. It did this by keeping the tolerances fairly wide. The 6.5 can easily digest fuel filtered to 5 micons for hundreds of thousands of miles. There are lots of ones running right now to prove this.

I suspect that most IP mechanical failure (of the newer, updated and hardened IP's) was/is due to lift pump failure and/or a dirty fuel filter resulting in vacuum for the IP supply or a blown hole in the dirty fuel filter.

In my mind the cost of adding additional filtration and the needed additional lift pump does not justify the small benefits gained.

If money is an issue then I think the best investment would be a simple pressure/vacuum gauge between the filter and the IP. This would alert the driver of all the above mentioned problems and allow speedy attention to repair.

Of course, if money is not an issue then go for it and get it all chrome plated too!

Just my .02 smile.gif

[rjwest]

Bufflo Guy , I see you have a 93 mech pump...
I had a 82, it had 2 filters. A disposable
prefilter and a secondary filter before Pump.

I think this was a much better set up than whaT I
HAVE ON MY 96. 1 filter that has a bowl to collect
all the junk so it can be recycled into the system.
Also the Electronic IP has an additional solenoid to Regulate and time Fuel. Plus much more complicated Rube Goldberg apparatus...
I believe this is where all the IP fails are...

My opinion The 94 and latter are " Cr*p "

[BuffaloGuy]

Could be. My OEM mechanical lasted 97K. The replacement the dealer has put on has went 115K so far. This one is the updated pump so we'll see how long it goes. I'm sure glad I have a mechanical IP. Others must like 'em too. Did you notice that when More Power did his survey for which articles guys wanted to see offered free one of the most popular picks was the one about how to switch from an electric IP to mechanical.

[MEDiesel]

I just ruined my injection pump with water in fuel. My question is- where should I locate another filter and what should it be ? Any help would be very much appreciated.

[rjwest]

From what i read, water seperators work best on suction side. I put mine ( perma cool ) on frame rail, See Post " 2 lift pumps "

I don't trust the OEM filter on firewall...

[MJEasly]

Racor has introduced some really interesting stuff. This (http://www.parker.com/parkersql/default.asp?type=2&id=27) really caught my attention.

[Edit] The link goes to the home page - search under fuel conditioning for RFCM (http://www.parker.com/racor/cat/english/images/fuel_cond/fuel_cond_pop.jpg) (Racor Fuel Conditioning Module)

[ 10-06-2003, 10:24 AM: Message edited by: MJEasly ]

[Turbine Doc]

UC here is some more part info for you on a vendor for the switches from www.go2marine.com (http://www.go2marine.com) they have some pretty good prices for the filters the part numbers are their listing

95713, Vacuum Switch, Racor 7" vacuum
1 @ $32.71 Each

83558, Diesel Spin-On Series Fuel Filter Model 660R, Racor 30 Micron body & filter comlete
1 @ $77.86 Each