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Johnontheroad · 07-06-2013, 10:17 AM

My '09 Camelot is due for a new fuel filter, and I happen to have one. But if memory serves, you need a certain procedure to replace the filter so you don't get air bubbles in the fuel line.

Seems like a simple job, but then many simple jobs have a gotcha that I want to avoid. So any tips would be appreciated. BTW, I think I have 2 fuel filters, a primary and secondary. I suppose the same procedure for both?

== John

Dick1142 · 07-06-2013, 01:19 PM

On my CAT 350 I simply run the engine to be sure everything is ok, then screw one off and replace it, then immediately start the engine again and let it run for about 5 minutes. Then repeat the procedure for the second filter. I install the filters dry, and have never had a problem. Dick

Dick1142 · 07-06-2013, 01:20 PM

John....ps...I see you are just about 60 miles from me. I am just up the river. Dick

Les Stallings · 07-06-2013, 01:47 PM

Yes John, you should have two filters. They are not the same. Be sure to use the correct ones. You need to pay attention to how the gaskets go...

Only change one at a time. Remove the filter and be sure that the center gasket that usually stays attached to the center post comes off since if you install the new filter with a new center post gasket and the old one is still there, you will have a leak for sure.

With the first fuel filter replaced, turn your ignition key on but do not start the engine. Around back you should be able to hear the lift pump attempt to prime the fuel system. Turn the key off after 10 seconds or so and then back on. Repeat this for 4-5 times. After the last time start the engine and allow it to run until the engine runs smoothly. It may stumble at first as the fuel system completely primes.

Stop the engine and repeat the process with the second fuel filter. All should be well.

You may find some gorilla installed your filters and that you need a strap wrench or a chain wrench to remove them. I keep a chain wrench in my tool box just in case. It also comes in handy when servicing the air dryer.

Good luck,

Parkers · 07-06-2013, 02:04 PM

What I do is fill the new filter almost full with fresh fuel just before I screw it on. This way less priming is needed and it should start right up after turning the key on for 30 seconds or so. Then let it run for 5 minutes or so and you are ready to roll.

Les Stallings · 07-06-2013, 02:17 PM

Quote:

Originally Posted by Parkers

What I do is fill the new filter almost full with fresh fuel just before I screw it on. This way less priming is needed and it should start right up after turning the key on for 30 seconds or so. Then let it run for 5 minutes or so and you are ready to roll.

If you do that you need to be VERY sure to keep things clean. A tiny bit of dirt can cause a lot of expense with fuel injectors. Any diesel fuel that you pour into the center hole will not be filtered. Trying to fill the filter using only the small holes around the edge is difficult.

Cummins does not recommend filling the filters. I tend to follow their advice.

Old Scout · 07-06-2013, 02:28 PM

YUP--where do you get "filtered" fuel to pre-charge the filters? Chances are you can get away with using unfiltered fuel but why take the chance that something gets in the filter. Depending on filter location, I also cover the open end of the filter with plastic from the packaging and then remove it just before I make contact to screw the filter [oil or fuel] on the engine/filter mounting.

walt2137 · 07-06-2013, 03:00 PM

Quote:

Originally Posted by Les Stallings

If you do that you need to be VERY sure to keep things clean. A tiny bit of dirt can cause a lot of expense with fuel injectors. Any diesel fuel that you pour into the center hole will not be filtered. Trying to fill the filter using only the small holes around the edge is difficult.

Cummins does not recommend filling the filters. I tend to follow their advice.

Pretty easy to do Les by using a nipple in the center hole and prefill the primary start the engine run a few minutes then use the fuel prim pump to fill the secondary by cycling the key on and off.

Mutt · 07-09-2013, 04:29 PM

Hopefully, you have completed the job by now, but if not...I have replaced both filters. I talked with a Cummins RV shop Tech and was told that they always fill the filters before installing them. I use a small funnel being careful not to let anything drop into the filter as I fill them. I replaced them one at a time, and ran the engine at about 1100 RPM for a few minutes to be sure that any air bubbles would pass through the infectors. And then replace the other one. Hope this helps.
David

walt2137 · 07-09-2013, 05:54 PM

Quote:

Originally Posted by Mutt

Hopefully, you have completed the job by now, but if not...I have replaced both filters. I talked with a Cummins RV shop Tech and was told that they always fill the filters before installing them. I use a small funnel being careful not to let anything drop into the filter as I fill them. I replaced them one at a time, and ran the engine at about 1100 RPM for a few minutes to be sure that any air bubbles would pass through the infectors. And then replace the other one. Hope this helps.
David

David I hope you didnt fill in the center hole of the filter as that is where the filtered fuel is suposed to come out and why i screw a 1 inch nipple in there and fill on the outside holes. A 1 inch pipe nipple will work on most filters 1 inch 14 thread even though the threads are not the same just snug it in.

Dutch Star Don · 07-09-2013, 10:51 PM

I tried on my first fuel filter replacement to put them on dry and then do the ignition on and off prime. It didn't work and I couldn't get the thing to start. I was panicked that I couldn't get my new coach to start. Finally, I filled the filters and it started right up. I change my filters once a year. I keep a set in the coach and install those when changing filters and put the new ones back in the coach as spares.

Les Stallings gave you good info, but I'll add that what he is calling a gasket is really a rubber o'ring with square edges. It will fit over your thumb and their should be a new one sealed in the plastic that protects the filter. As Les said, make sure the old one comes off and the new one goes on. Make sure both filters have a new o'ring before you open them so that when you're done, there should only be two left. The old ones really don't look any different than the new ones after they're removed.

I have a small one gallon fuel can that I fill with diesel. I wash my hands and then use my thumb to cover the center hole of the filter (output hole) and then pour the diesel fuel around the outer edges until the filter is full. You can change the other filter or as some do, fire up the coach, let it idle, shut down and change the other one.

H. Miller · 07-10-2013, 05:36 AM

Probably depends on the engine (op left us guessing) but the Cummins Operation & Maint. Manual for the ISC engine says DO NOT prefill the fuel filters as there will or maybe damage to the low pressure (lift) pump.

moisheh · 07-10-2013, 06:20 AM

Mqaybe Cummins does not want you to prefill but Fleetguard filters ( part of Cummins) has a diagram on the side of the filter showing you how to prefill. Fleetguard filters come from the factory with a plastic plug for the center hole. Some people use ATF instead of diesel as it is very clean.

HD4Mark · 07-10-2013, 06:33 AM

I also tried replacing the filters one at a time dry on our Cummins ISC. It would not start even after the turn the key on for 15 seconds then off many times dance. I stuck my clean thumb in the center hole and had DW carefully fill the filter through the small outside holes than are the inlet and bingo, she started right up.

Ask any diesel shop and I am sure they will tell you that is how they do it. They do not have time to screw around priming it with the key and yes Fleetguard filter have little picture showing you how to prime them. My buddy that works for Detroit diesel said the same thing.