Use of Non CAT Fuel Filters on CAT Electronic Engines (PUTTING ENGINE AT RISK )

[Joel Weiss]

Pre-filling fuel filters is a standard practice with a service that is non-cat
and uses brand X fuel filters that are 10 micron. Dave Atherton Retired Cat Mechanic

With all due respect, I watched a technician at a CAT shop in San Antonio prefill my filter and I didn't object because I thought this was pretty standard practice as long as clean fuel was used and the tech was careful to only pour the fuel into the inlet ports, not the outlet.

[Dave Atherton]

Joel, anytime a Cat 2 micron fuel filter is pre-filled reguardless how the fuel is poured in filter,
a person is taking a chance of contamination of raw unfiltered fuel. In several cases where fuel
filters were serviced when I was working for Cat Dealer ( cat engine did not have the hand
primer pump ), we were required to strain raw fuel with paint strainer into a gallon jug and
keep on our service truck, than pre- fill the secondary 2 micron like you just mentioned. the
only thing different,  the fuel we pre-filled filter with was strained as per company policy. This
was suggestion I just passed on that taken a lot of meaning prevent fuel contamination with
again Cat Dealer where I worked. Dave Atherton Retired Cat Mechanic

[Edward Buker]

I had posted that the fuel passed through the filter once and that is in error. The fuel schematic for a C12 has the return from the fuel rail go back to the filter housing as Dave pointed out. There is also a tank return line coming out of the filter housing. It is not clear in the schematic where the fuel in the filter housing is being directed, but after thinking about it, they only way we could have our fuel tank continually heat up as we drive, (I have seen 130+ degrees on the Alladin) is if the fuel that absorbed heat at the fuel rail was at least in part returned to the tank.

Thank you Joel and Dave for picking up on that error and helping to get this right.

Later Ed

[Dave Atherton]

Joel Weiss, digging deeper into practice of Prefilling cat fuel filters that might be of interest with Cat Electronic engines. Cat Service Bulletin, 01/04/2000. Fuel filter prefill practices are harmful to fuel systems, and should always be avoided. Proper fuel filter maintenance requires priming the replacement filter at the time of install. Many operators and mechanics prefill replacement filters with used fuel from spent filters. Practice allows dirty fuel to bypass the fuel filter media and enter the clean side of filter. Prefilling a fuel filter compromises integrity of an engine fuel system by allowing unfiltered fuel to enter the system and contaminate sensitive fuel injectors and pumps.

A priming pump should be used to prime replacement filters with fuel. It is important to prime, and not prefill, replacement filters in order to ensure that fuel systems receive filtered fuel only.

Joel going back on my answer that I posted, It was Cat dealer policy where I was employed
to filter raw diesel fuel with paint strainer into gallon container and carry on service truck if
need that required prefill of fuel filter. What makes the Cat 2 Micron fuel different from others
such as the 1R-0749 fuel filter used on Cat C-12, High Efficiency fuel filter with Stay Clean Valves.

Replaced all Standard Fuel Filters 01/04/2000. the stay clean valve will prevent unfiltered fuel, which contain abrasive contaminants, from entering the clean side of fuel filter. Unfiltered fuel will cause damage to the engine fuel system. 

Dave Atherton Retired Cat Mechanic

[Michael Rump]

Hi Dave,

Thanks for taking the time to share your knowledge.  Just a quick question on priming the cat filters;
My C12 does not have a fuel filter priming pump.  Therefore, it is my understanding from the threads above that the filter should be installed without fuel in it.  It that correct?

Best to you!

[Dave Atherton]

Michael, with no priming hand pump on fuel filter base, there should be a hand push primer
on your primary filter with the water plastic bowel on bottom. Or you possibly have installed
the Winn filter setup with electric pump and little black box with indicator lights that located
should be on right rear of motorhome. Dave Atherton Retired Cat Mechanic

[Jerry Emert]

Michael, with no priming hand pump on fuel filter base, there should be a hand push primer
on your primary filter with the water plastic bowel on bottom. Or you possibly have installed
the Winn filter setup with electric pump and little black box with indicator lights that located
should be on right rear of motorhome. Dave Atherton Retired Cat Mechanic

Dave, I was going to ask about priming also.  Mine had the electric one that does not work and was damaged by high heat after the exhaust pipe fell off.  It didn't work before anyway.  With no priming pump, how do I "prime" after changing the fuel filter?  Thanks
Jerry

[Dave Atherton]

Jerry, what has happen that you builder add on failed. look at your primary fuel filter to see
if there is a hand pump at filter base ( should be looking at  black rubber hand push bulb ) If
not than go  to plan B the way Cat made engine and before install into motorhome. two suggestions depending how easy it is getting to fuel filter base. there is air bleed screw ( hex )
that you can loosen install new 1R-0749 fuel filter dry. with bleed screw open key on turn engine
for 30 seconds aprox and let starter cool than again. there is a little gear pump down in front
of engine that will pump into the fuel filter with air bleed screw loose. About the second time fuel should be coming out of bleed screw and engine want to start. engine will idle a little rough
untill air is gone through system tighten bleed screw. Plan B, and like most people do and can
be done is to strain fuel through paint strainer into a gallon container and pre fill filter. However
my post above cat does not recommend this. Again in the next thought had policy for service
tech's if required to pre filter raw diesel fuel and prefill fuel filter and start engine. I cannot
tell you how you should address the above but fuel is pre filtered before prefilling fuel filter
with clean diesel fuel. Return to Joel post he viewed a cat tech pre fill his fuel filter. Hope this
help with thoughts. Dave AthertonRetired Cat Mechanic

[Joel Weiss]

Or you possibly have installed the Winn filter setup with electric pump and little black box with indicator lights that located
should be on right rear of motorhome.

I have this setup but I never realized that the pump was capable of priming both the primary and secondary filters.  In fact the Cat technician I wrote about used the electric pump to prime the primary but then prefilled the secondary CAT filter.  I guess he didn't realize the Winn pump would have filled both.

[Lee Welbanks]

Dave,

If I remember correctly the inlet of the fuel comes into the outside of the filter and out through the middle. In theory you could take a 1"-14 bolt with a O-Ring stop on it and seal up the mount and then pour the fuel into the outside and your fuel would be filtered? Or am I all wet as usual.
I have a hand pump with a discharge filter on it that I fill my fuel jug with. Most shops that I've seen use a fuel cart that has filters on the discharge side of their pump,we had one and  I know Cat here in Phoenix, Az does it this way.

[Dave Atherton]

Lee , yes that would work great, why is fuel filter subject so important with the Cat Electronic
engines. The Engines has two types of fuel injection systems that is completely different than
others engine mfg. There were many bugs at first untill cat  got it right. Engines starting from
3126A model to the C-9 of which all have the Cat heui system. Than starting at C-10 up to
C-15 for motorhomes, cat now has what is called a electronic high pressure injection system.
Both injections systems are very good but different. End result, the post on the working of
ECM and fuel filters 2 micron, the engine was designed around the filtration of fuel through
fuel filter restriction and engine derate when service is due. Dave Atherton Retired Cat Mechanic

[Lee Welbanks]

Back in 70's & 80's we used to have serious problems with fuel, mostly water, the advent of the water separators solved most of that problem but we still carried a case of fuel filters. We would never buy fuel at any place that didn't have a big volume turn over.

[Edward Buker]

A word of caution....The fine mesh nylon and paper automotive paint strainers are available in 125 to 400 micron mesh, typical is 200 micron. The most damaging particle size to our fuel system is in the 5 -10 micron size range. This practice of filtering with paint strainers is ineffective in screening out the particles of a size distribution that are of most concern. To put this in perspective, 1/1000 of an inch is 25 microns, a human hair diameter is 40 to 90 microns.

This is a pretty good article .. The diesel fuel ISO standard limit for particles >4 microns is set at about 1 million per gallon so don't expect unfiltered fuel to be clean.

http://www.howcleanisyouroil.com/DIESEL-FUEL-OIL

I would opt to get a priming system running as a first choice or use Lee's method of filling the filter with the center hole blocked off. Dave's method of cranking with the bleed screw open sounds like a safer method of getting filtered fuel to the engine. I would not be concerned about filling the pre filter (mine is rated at 30 microns) with raw fuel, the final filter rated at 2 microns is the one to be concerned about. Hope this helps.

Later Ed

[Dave Atherton]

Gentleman, the post ( non-cat filters puts electronic engines at risk ) has very positive
feedback via of members. Mainly with cat electronic engines that has a fuel system
that is very different than other engine builders. In the early days as Lee stated, would
carry a box of fuel filters on his truck to make a trip says it all. The practice of handling
diesel fuel, changing fuel filters did not seem to be a big thing. Than Cat built the 3126
and 3176 electronic engine with a computer and start of the fuel system which we
are now using today in our cat electronic engines. This has been a very hard subject
for many, many years with Contractors, Trucking and than the motorhome people
to understand, most all problems with Diesel engines start at the fuel system. 
In most cases today are minor in nature but than compounded by not understanding
just how important clean fuel and correct cat fuel filters affect your cat engine and
added cost to ownership. Again gentleman, this positive feed back on this subject
with so many good replys has been great. Dave Atherton Retired Cat Mechanic