Auxilliary Fuel Filter

[98silverado]

Hello! I've got a '98 Silverado 6.5TD and I'm thinking of adding a racor type fuel filter between the fuel tank and the lift pump. Is this a good idea and what type of filter would be best?

[Brianlar]

That's a great idea, especially if you use the 2 micron unit with the water seperator. Your engine will thank you by being more reliable than it would otherwise. :D

[NH2112]

Put the factory filter before the lift pump (and Racor) or else that expensive Racor will bravely sacrifice itself so the inexpensive factory element can live longer.

[98silverado]

Thanks for the replies fellas! You mentioned putting the factory filter upstream of the Racor - on my '98 it sits at the back of the engine right by the Stanadyne injector pump - Ho do i relocate it??

[NH2112]

I did something similar on my Sierra 1500 with swapped-in 6.2L. When I got it from my friend there was a generic Stanadyne "glass" filter on the firewall, which I replaced with a Racor 445 as my sole fuel filter. My 2-micron elements weren't lasting at all so I took the Stanadyne Model 80 from my project K10 and mounted it on the radiator support, underneath the air intake hose. This is my primary filter, with the finer Racor being the secondary. All I did was run a new rubber line from the end of the factory pipe (at the right rear of the intake manifold) to the Model 80 inlet, then from the Model 80 outlet to the Racor inlet. The Racor outlet hose goes to the injector pump. I zip-tied the 2 new fuel lines to the heater hose for neatness and security, and if I had to guess I'd say that 12 feet was more than enough. Now I have the coarse Model 80 filter to trap gross contaminants (if anything that can be pulled through the sock in the tank can be called "gross") and the 2-micron Racor element to keep my injectors and pump healthy for a long time.

I've put close to 30K miles on since installing my dual filter setup in May 04 and have only had to change them once, in November 04, due to a fuel problem. It ended up not being caused by clogged filters, but when I cut the primary element open I was really surprised at how much slime and silt was in there. I didn't cut the secondary element open to see what got past the primary, but the next time I will. Maybe I'll get the box from under the dash of my K10 that converts the millivolt signal from the WIF probe to a 12V signal for the WIF light and wire up the WIF circuit, it would have been interesting to see whether the primary filter truly was clogged after 25K miles.

[jbplock]

Phil, Nice setup!

Another aftermarket filter to consider is the Stanadyne FM100 (http://www.reliableindustries.com/catalog/STN/fm100.php). It's a high quality unit and reasonably priced. The filter elements come in various sizes and micron ratings. It can also be fitted with a heater element, which might be important in the winter if you used the 5, or 2-micron elements. I used a 30 micron FM100 as a Pre-Filter (http://community.webshots.com/album/77018086bLHHHC) for the AC lift-pump and Mega Filter (http://community.webshots.com/photo/67970835/67971249ZTDzat) setup on my 03 Dmax. A good place to buy the FM100 is from Reliableindustries.com (http://www.reliableindustries.com/).

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[More Power]

All good advice....

I had a discussion with a NE regional service rep for the 6.5 a few years ago about lift pump reliability. He told me that about 50% of the failures they analyzed were due to water/corrosion and the remaining 50% were due to particle contamination and jammed valving (usually due to a failed injection pump putting metal/ceramic into the return fuel, then recycled).

He couldn't officially recommend a prefilter before the lift pump, but indicated it would be helpful, especially for those who are more exposed to contaminated fuel.

MP