Jambbii

When do I need to change the water seperator? And how often do I need to change the fuel filter?

Thanks

kandgo

I change my fuel filter every three oil changes,some say every other,genos garage sells kits to change the oil twice and fuel once.So weigh it out. I get my fuel at a local place that sells as much or more than a truck stop along the highway and have never gotten any water in any of my fuel filters dozerstractorsor trucks. As far as the water in light indicator{if this is what you are meaning as water seperator} at the bottom of the fuel filter if it is not broken why change it out?? One thing in the fuel area that gets over looked is the fuel pre heater screen,the service kit from cummins is only around $8.00 from dodge it is as high as $42 and while you are there you can pickup some oil and fuel filters. Goodluck Rick

infidel

Best way is to install a fuel pressure gauge to indicate when to change. It will pay for itself with just a few eliminated needless filter changes. I usually go 20k and have never had the pressure drop, but you never know, one bad tank is all it takes to plug things up. I know one guy who went 62k on the filter that came stock with his truck and another who barely made it out of the fuel station before plugging.

Pumperdude

Easier question than you think.If you changed the fuel filter,you have aready changed the fuel water seperator......Fuel filter = fuel water seperator ......I second the infidel with a fuel gauge suggestion.You just cant have too many gauges

Jambbii

Thanks for the advice guys. Should I really invest in a pressure gauge, if so can I run it in the cab?

Dieseldude4x4

I've not heard of anyone putting a FP gauge on the 12 valve trucks.

infidel

It's not a necessity to have a FP gauge in a 12 like it is on a 24 valve but they sure come in handy for filter changes and diagnostics. Most every 12 valve will need one at least temporarily sometime in it's life to pin down fuel delivery problems, otherwise you end up just throwing parts at a problem. 24s have lift pumps that go out, 12s have a overflow valve that fails, usually slowly. Best to catch it before it's a problem.
As for fuel in the cab, that's it's own debate. I personally see no problem with it. On a 12 you must use a pulsation dampener or needle valve to snub lift pump pulsations or the gauge or electrical sender is doomed to an early death if you can even read it. Because of this any leak will only amount to a slow drip. As far as safety, another member here said it best, "If you throw a lit match in a puddle of diesel fuel all you get is a wet match."

I posted instructions that many folks have followed with excellent results here-
https://www.dieseltruckresource.com/...threadid=36212