Monaco Cayman fuel filters

[joelsr]

I'm getting ready to change out my primary and sec. fuel filters. I've talked to two service types at Cummings and one said not to prefill but to go through a priming procedure and the second person said to prefill the primary but go through the priming procedure for the secondary. Any ideas out there? Thanks!

Ciao and God Bless

[joelsr]

I'm getting ready to change out my primary and sec. fuel filters. I've talked to two service types at Cummings and one said not to prefill but to go through a priming procedure and the second person said to prefill the primary but go through the priming procedure for the secondary. Any ideas out there? Thanks!

Ciao and God Bless

[William Willard]

joelsr -- I`ve done it both ways, but now I fill the primary, & do the priming procedure on the secondary-- The secondary will filter the fuel you put in the primary, before entering the injectors -- Much easier on your lift pump -- Be sure & do one at a time -- Bill Willard

[joelsr]

Thank you Bill
Joe

[Gary RVRoamer]

All the Cummins engines for the last several years have electric lift pumps and the Cummins recommended procedure is to use the lift pump to prime both filters rather than pre-filling. Basically just turn the key on for 30 seconds and repeat 2-4 times to fill each filter. That way there is zero risk of fuel contamination. And its easier too!

I got this straight from my Cummins factory rep.

[William Willard]

Either way you choose to do it, the most important thing is "one at a time" -- If you get both filters empty, you may in for a bad day -- Bill Willard

[joelsr]

Thanks to all
It seems like you are saying the same thing. Remove and prime the primary and then remove and prime the secondary. I agree that having both filters empty will let me in for a bad and long day. The secondary going to be an exercise to get to and remove. Seems like they put down the engine and builit the coach around it. It would have been better if both filters would have been installed in tandem at the rail where the primary is located. Oh well! Noone said it would be easy. It took a 1/2" drive and cheater bar to get the oil filter off. I think they installed it with an air impact wrench. The oil filter gasget was as flat as it could get w/o spilling out oil.
Ciao and God Bless
Semper Fi

[The Danes Are Coming]

Hi joelsr

Please check out this thread. I started this in February when wanting to change my filters.

This is the advice that I got, in writing, from Cummins:

1) You may select to put the primary filter on dry if you like or you can pre-fill it. Both methods are OK. When changing the secondary filter it must however go on "dry" - don't pre-fill this one.

2) Prime the filters many times (5 or 6) by turning on the ignition for 30 seconds - then switch the ignition off for 20 seconds.

3) Crank the engine for 30 seconds - no more and no less. If the engine starts then obviously stop cranking. If it doesn't start then wait for 2 minutes before cranking a second time. The starter motor will run to hot and may "burn" if you crank for longer time or if you crank it over and over. Start cranking a second time if necessary, and if this doesn't work, then wait 5 minutes before cranking a third time.

4) Most filter changes goes real smooth and you can start up without problems. In some cases the filters will take long to prime and it will not go as smooth. In very few cases the filter change causes problems that will require a Cummins approved technician to crack open the fuel line and sort out the fuel flow. THIS MUST NOT BE CARRIED OUT AS A DO-IT-YOURSELF JOB BECAUSE THE PRESSURE IN THE FUEL LINES ARE EXTREMELY HIGH AND CAN CAUSE SERIOUS DAMAGE TO YOU OR OTHERS.


In another mail from Cummins I was told that when filling the primary filter with diesel it is advisable to plug the big hole in the centre of the filter and fill only through the perimeter small holes. This ensures that the diesel that it poured in is being filtered by the primary filter before being passed on to the secondary filter.

I know that there are different opinions on what to do, but this is what I do:
Fill the primary filter before it goes on (fill through small perimeter holes only). Secondary filter goes on dry. Get the engine to prime the filters and do this repeatedly. Please notice that the secondary filter is located in a very tight spot and can be difficult to get off. I had to disassembly the filter bracket to get the filter into a place where you can get a good grip and even then I had to ask 2 strong Mexican guys to twist the filter off for me. I wasn't strong enough to do this my self and I even wrecked a filter wrench in the process.

Good luck.

[Lennyzx11]

I ran my Cayman out of fuel this year. (I know, I know) and here's a couple of bits of information. I've owned Cummins (Dodge Ram) since 96 and worked as a mechanic at their dealer for a year as a Cummins tech.
The lift pump will fill the filters back up. On top of the filter canister mounted on the engine is a allen screw/plug that can be removed to let the air come out as the fuel goes in. (ie. vent) when the fuel dribbles out, the fuel system is full and replace the plug. I got to mine through the hatch in the bedroom floor.
Second, you don't have to continously crank the starter. The key can be "bumped" to start momentarily, the lift pump will come on for a short period of time. (I want to say 30-45 seconds.)Then it must be "bumped" again.
If you're alone this gives you enough time to run back in the bedroom and check for fuel coming out ! By the way, laying a rag over the vent bleed hole on the filter canister will keep diesel from squirting up and all over when filled.
With plug reinstalled, attempt to start, it may run rough as all injectors are purged of air and even die a few times, restart and eventually it will smooth itself out to that normal idle.
The older Cummins in some cases had to go one extra step and loosen each individual line to the injectors to purge air in order to restart, but that's not the norm any more.
Oh yeah, to avoid all this, Check that Centroid Fuel sending unit's accuracy, that's what got me to do the "red can boogie" on the side of the highway in Vermont!

[joelsr]

To prime the fuel system on Cummins midrange engines with electronic
fuel systems having an electric lift pump, use the following procedure.
This applies to ISB and to ISC/ISL engines.

The need to prime the fuel system sometimes follows having run out of
fuel. The following instructions assume that enough fuel has been added
to the tank that the fuel pick-up is able to suck fuel from the tank.
If the vehicle is parked on an uneven surface, considerable fuel may be
needed (as much as 20 gallons).

1. Turn the key switch on.

2. Wait about 5 seconds. (The lift pump will run for about 5 seconds
after turning the keyswitch on.)

3. Engage starter until engine turns over a few times (just a second or
two).

4. Keep the key on while releasing the starter - LEAVE THE KEY IN THE ON
POSITION for 30 seconds.

NOTE: the purpose of this step is not to try to start the engine but
to run the lift pump; the ECM must see that the engine is turning
before it will command the lift pump to start. If the key is
left on after the engine has been turned over for a few seconds,
the lift pump will continue to run for 30 seconds total. This
pumps fuel into the system and forces air out. You may not be
able to hear the lift pump from the driver's seat on a pusher RV.

5. Turn the key off.

6. Repeat steps 1 through 5, four or five times

7. Crank the engine for 30 seconds. (The engine may start, but likely
not the first time or two.)

8. Wait 2 minutes. (This allows the starter motor to dissipate the heat
developed during step 7.)

9. Repeat step 7 NO MORE THAN FOUR TIMES

Note: this procedure may have to be repeated

If the engine does not start, there is some issue other than priming or
filling of the fuel filter. You may need to contact a Cummins dealer or
distributor to help you start the engine.

[joelsr]

Sorry for not mentioning that my last post is what I was emailed from Cummins.

[jimlawman]

A few friends and myself have started changing our own fuel filers after learning that the tiniest spec of dirt (5 microns)can clog injectors and damage the engine. We change the primary first and do not pre-fill as you may induce some dirt directly into the engine. It will take several iterations with the ignition on for about 40 seconds to fill the filter and get a start. My friends ISC started after 6 iterations, my ISL took 11 iterations of key on, wait for electronic sequence of fuel pump, key off. I would try for a start after 5 iterations and every 3 thereafter. Then we change the secondary filter and go through the same sequence. We wear clean surgical gloves, clean the area around the old filters before removing them and are very careful not to induce any dirt into the new filter. We started doing this and lubing our U joints after seeing some pretty slipshod RV shop work.

On the MCOA Forum you can find an owner that pre-filled in violation of his engine manual and ended up with expensive engine damage that Cummins refused to warrant.

Good Luck and Happy Travels,

jimlawman

[quikduk]

I just changed both my primary and secondary fuel filters this past weekend. Cummins told me a different procedure. BTW, I have a C8.3 with mechanical Bosch fuel pump.

1. cleaned and changed the primary fuel filter (bigger one located on the passenger frame rail)

I was told to fill this filter to overflowing with clean, filtered diesel and to pour the fuel through the side holes, NOT in the center hole so that the fuel could be filtered properly.

2. cleaned and changed out the secondary fuel filter (small one on the passenger side front of the engine)

I was told to also fill this filter to overflowing and to fill by the same method.

I used clean NEW #2 diesel and filtered it through a screened funnel into a clean receptacle (can). I then carefully poured this through the side filtering holes to remove any other foreign matter via the filter medium.

I had to crank the engine for 2-3 seconds a total of three times before the engine would fire and run. It ran smooth with no issues and a 14 mile round trip at varying speeds and loads proved that there were no issues with the installation.

Perhaps the electronic units are different.

As always, YMMV.

[JohnB]

I changed mine this weekend, the secondary took a 24" breaker bar to get broke loose using a Cat belt type filter wrench. I pre-fill both filters after blocking the center hole (clean side. As long as you only let the fuel go through the filter in the correct direction, outside holes to center hole, you are fine.