Fuel Filter/ screens

[shendren]

Illflem talks about 3 fuel filter/screens. i thought there was only 2. the prefilter, then the filter. where is the 3rd? how often do you change/clean it? has anyone cleaned the prefilter? was it dirty? how often do you clean that one? thanks, scott...

 

[illflem]

Scott, the third one is in the tank on the bottom of the tank module. The sloshing of fuel in the tank will usually keep it clean unless you get a bad load of fuel. Cleaning the screen in the fuel heater depends on the fuel you get. I cleaned mine every 10k when changing the main filter but quit when it was always spotless, that was 140k miles ago. Of course I get most of my fuel from my own tank were it is filtered before going down the hose. If you get your fuel from a busy station I feel you only need worry about the main filter. I am now changing my main every 20k and probably could go longer. Seems like one member here reported going 62k with the main filter that came new with his truck before it finally plugged up, his prefilter was clean.

 

[Joe G.]

Bill,



I went something like 60K on my last fuel filter. Then I got worried because you mentioned a filter failure with a D7 because it was used too long so I changed it. I cut this one open and checked. The media was still strong so I dunno how long it would have lasted. It was pretty black, but I still had good pressure. I always check my prefilter at oil change time and it's always sparking clean. The only place I buy fuel if I can is CFN. However, I do carry an extra fuel filter just in case I get a bad tank full.

 

[C Schomer]

My heater screen always looks clean but I blow it out anyway. Parafin and bacteria aren't always easy to see! Craig

 

[illflem]

Yeah Joe, Cat was recommending changing fuel filters at least once a year to avoid media breakdown, I found out the hard way, about $4k. This was years ago though, filter media has changed and this may not now apply. 20k is about a year for me. I try to change the main before the cold weather sets in due to my dislike of side of the road in 0° repairs.

 

[Blakers]

recommending changing fuel filters at least once a year to avoid media breakdown

Does the media break down? I have diesel tractors around here with filters that have been in for 20 years and they are still ok.

 

[pwknapp]

I was hauling a large load (33k) (wide load) lots of wind resistance,and lost power, lots of white smoke. Left load at truck stop and had cummins mid south check it out. Timing slipped because of pre filter being clogged. Now check it when I change regular fuel filter and is usually very clean. Guess one bad load of fuel can get you.

 

[Joe G.]

I would sure like to hear the explanation of how the timeing could slip if the prefilter was clogged. That doesn't make a bit of sense to me. It should just run out of fuel in that case which should not put any more strain on the injection pump than just ordinary running out of fuel. Maybe I'm wrong but I would need know how that could happen to believe it.

 

[illflem]

Originally posted by Blakers





Does the media break down? I have diesel tractors around here with filters that have been in for 20 years and they are still ok.

Blakers, I used to feel the same way until until my D-7 had $4k worth of injection pump damage due to what the Cat dealer said was failure of a 3 year old filter. I didn't use the tractor much, it sat a lot. What they said was that after long periods with just old diesel sitting in the filter chemical reactions can take place with the adhesives used in the filters. Once the filter starts getting clogged the fuel finds the easiest way around and finally cuts lose flushing all the gunk that the filter has trapped into the pump. Like I said modern filters may be different, a lot has changed in 20 years. If I were you I'd change your 20 year old filters for modern ones, very cheap insurance. I also had a many years old Goldenrod fuel filter on my fuel tank rip, luckily the filter had a clear plastic bowl at eye level, I caught it right away.

 

[Blakers]

I wonder if there is some additive in the fuel nowadays that acts as a solvent to the adhesives used in filter construction? Seems crazy they'd use a component in the filters that beaks down in the fuel they are made to sit in. My Cletrac dozer has two big filters in series, so I guess that probably saves things, but I'll have to pick up some filters next time I run her.

Blake