Fuel pump location

[45acp]

I have a 2002 Dynasty with a Cummins ISL 400 engine. I would like to replace the fuel filter/filters but do not know where to look. I believe there are two pumps are their filters in front of both? Help would be appreciated. Also any advise on changing them and not losing prime pressure?

[rpasetto]

If you're looking for fuel filter locations, the primary filter should be at the rear of the engine on the driver side and the secondary filter on the passenger side. Check your owners manual: https://www.monacocoach.com/rv-owners-manuals

[Lowflyer1]

I took a look at the on-line Owner's Manual for 2002 Monaco Dynasty and it is confusing. For Routine Maintenance Recommendations it says:

1. Change the fuel filter at every oil change interval.
2. Change the fuel-water separator filter every 12-18 months or every 25,000 miles.
To me, that's 2 filters. Depending on your tank condition and fuel supply, I'd change it/them at least once/year.

Then it says: "Fuel/Water separator is located in rear engine compartment on the left side of the frame."
It has a diagram that only shows what looks to me like the primary with the water separator/sediment bowl. No mention of the secondary filter.
Then near the back of the manual the filter/belt chart shows both Primary and Secondary.
These manuals do have lots of errors and sometimes more research is required.

My 2004 HR has 2 filters at the back of the engine compartment. The fuel goes from tank to primary filter. At startup (priming process) lift pump sucks fuel thru primary and pushes it thru secondary filter to the injection pump. Once the engine is running/after approx 1 minute, the lift pump stops and injection pump takes over sucking the fuel thru both filters.

There has been a lot of debate prefilling vs. not prefilling the filters and some manuals actually say not to prefill (to ensure only filtered fuel goes to the injection pump). Then turn on the ignition on for 1 minute (may vary a bit depending on the coach). Repeat this maybe 5-6 times until the system is primed. You should be able to hear a different sound on the lift pump when the system is primed.
Then you should be able to start the engine.

I've seen and heard this done different ways. Some show to cover the center (outlet) with a plug or your thumb and keep the fuel from going to the clean side. Some just fill the entire filter. The key is to provide clean fuel to the injection pump.

On my first filter change, they were so fricken tight that I thought I'm gonna break something. Definitely needed a sturdy filter wrench on those. Maybe the gaskets were not lubed.

The lift pump has a check valve and if it works properly, should prevent fuel from going back to the tank. It may help to have a full tank of fuel to prevent/slow the flow back to the tank.
Typically these filters have 2 O-rings, a small one around the threaded stud and a large one like in an oil filter. Make sure the old gaskets come out before installing new ones. The filters I have also have a diagram that shows to lube the new gaskets. I use engine oil.


Hopefully someone that has the same coach as yours can provide better info.