Need advice on fuel filters

[Joe & Bonnie]

I have an Cummins ISC in my Holiday Rambler. I'm planning on changing my fuel filter before heading to TX late this fall. Should both filters be changed? If only one needs changing, which one? Am thinking it's the filter with the water drain but not sure. Am also thinking of doing it myself. Any help or tips would be appreciated.
By the way, which is the primary filter? The one with the drain or the one without?

[OneRVer]

Your primary filter is the one mounted to the engine. How long has it been since your last filter change. I change both of mine each year. There should be a hand pump on the primary filter. If so, replace the filter dry, pump until you can no longer pump. This may take a while. Then start your engine and hope for the best. Rough idle and some white smoke at first is not a problem and should only last a few seconds.
With the water separator I always fill the filter up by pouring diesel into the filter then installing, messy. Good luck.

[DtBt]

There is no hand pump on an ISC. There is a electric lift pump that cycles each time you turn the key on. I change both of mine once a year. Change secondary only, leave dry. Cycle key on for 10 seconds. Repeat at least 10 times. Start engine for a couple of minutes. Replace primary and repeat. In this manner you are less likely to get the injector pump air locked and refusing to start engine.

[OneRVer]

Quote:

Originally Posted by DtBt There is no hand pump on an ISC. There is a electric lift pump that cycles each time you turn the key on. I change both of mine once a year. Change secondary only, leave dry. Cycle key on for 10 seconds. Repeat at least 10 times. Start engine for a couple of minutes. Replace primary and repeat. In this manner you are less likely to get the injector pump air locked and refusing to start engine.

Electric pump. That must be nice.

[rpasetto]

You should change both filters annually along with engine oil and filter, as part of normal maintenance as per Cummins. With an electronic engine, I've replaced both filters together, then cycled engine power on 30sec-then off-30sec. I usually repeat three or four times before going to start. I've also done it the way DtBt recommends, one filter at a time. Some will pre-fill the filters with diesel fuel; this is not necessary with the Cumins electronic engines because the lift pump will fill your filters. Cummins recommends against ever pre-filling the secondary filter.

[ejm4]

Fill both filters with fuel before installing. Do as quickly as possible to lessen the chance of air entering the fuel system.

[OneRVer]

Quote:

Originally Posted by ejm4 Fill both filters with fuel before installing. Do as quickly as possible to lessen the chance of air entering the fuel system.

Filling the primary with fuel before installing it is just asking for trouble. This fuel will NOT be filtered before entering your fuel injectors. As stated above, you have an electric fuel pump. Use it.

[itdave]

Joe,
I would tend to follow advice from people with similar chassis and engine, each manufacture has different recommendation for how things should be done. On my 06 HR Endeavor there are two filters one located in the back on the passenger side, the other is located behind the radiator for the dash AC second to last compartment on driver side. HR and Cummings recommend changing both of the filter at least annually As far as pre filling, changing one at a time etc. each mechanic seem to have their own process that they swear by. Just make sure dirt gets into the fuel systems while making the change.

[ditto]

Attended camp freightliner last fall. They recommend using a rubber plug in the center (threaded ) hole ...fill filters through smaller perimeter holes so fuel is filtered...on my cummins 400 ISL