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GaryKD · 02-07-2008, 01:54 PM

I prefill my fuel filter and water separator. I get eveything ready to take off the old filter. Prefill the filter, via the small holes. Take the old filter off, clean the flange, moisten the new gasket and install the new pre filled filter or water separator. Since fuel continues to pour out of the opening after breaking the seal on the old filter, I try to get the new filter on ASAP. After pre filling the new filter, from the time the seal is broken, on the old filter, I can have the previously mentioned steps completed in less than 10 seconds. This may sound like overkill, but it minimizes the amount of air in the system. I've changed the filters 3 times and all went well.

Route 66 · 02-07-2008, 02:02 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Since fuel continues to pour out of the opening after breaking the seal on the old filter, I try to get the new filter on ASAP. </div></BLOCKQUOTE>

Indeed it does.

Sixpack98 · 02-07-2008, 02:38 PM

When I had my chassis serviced at the lcoal Peterbilt they prefilled the main filter, had me turn the ignition on a off a couple of times and started the engine. They then instlled the secondary and, again, cycle the ignition swithch a couple of times. Engine started right up. Shop foreman said they have been doing this for years and he said never prefill the secondary, too much of a chance to introduce dirt, etc and the next filter is the injectors.

Dave Fernandez · 02-07-2008, 05:26 PM

A Cummins tech told me that with the new electronic engines you do not need the fill the fuel filters when changing them. He said when you change the filter turn the ignition switch to on position until the boost pump stops and repeat this at least three times and it will fill the filter. You can than start the engine without a problem. I do this and not had any problems when I change the fuel filter.

Camelot Camper · 02-07-2008, 07:05 PM

I went to the Cummins facility here in Fort Worth this morning and also spoke with Cummins Tech Support. Both gave me the same directions for MY engine, which is an ISL400 with CM850:

The filter/water separator that receives fuel directly from the tank should be prefilled with fuel because that fuel will be filtered by the primary filter before entering the lift pump. Run the engine now before changing the primary filter.

The primary fuel filter should be changed last so that it traps any fuel contaminants from changing the filter/water separator. The new primary filter should be put on EMPTY so that it can be filled with fuel using the lift pump priming procedures, which are: Ignition ON (not start) for 30 seconds then OFF for 10 seconds. Repeat same ignition cycle 3 or 4 times to allow the lift pump to fill the primary filter and purge the air out the bypass line. Then start the engine.

So in my case with my engine, everybody here in this thread is right with one filter or the other.

Thanks for all your input

CC

Sixpack98 · 02-08-2008, 06:10 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The filter/water separator that receives fuel directly from the tank should be prefilled with fuel because that fuel will be filtered by the primary filter before entering the lift pump. Run the engine now before changing the primary filter. </div></BLOCKQUOTE>

CC,
I always thought the Primary filter (FS1003) was the water separator and the secondary filter FF5488) was just before the injector pump. Sounds like Cummins has a different description.

Camelot Camper · 02-08-2008, 06:23 AM

Yep, you're right. The Primary Filter is the Water/Separator (FS1003) to be changed first, and the Secondary Filter (FF5488) feeds the lift pump and is changed last. It's still all new to me, but I'll try to get it straight.

Thanks,
CC

Ecker · 02-08-2008, 07:04 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Camelot Camper:
Yep, you're right. The Primary Filter is the Water/Separator (FS1003) to be changed first, and the Secondary Filter (FF5488) feeds the lift pump and is changed last. It's still all new to me, but I'll try to get it straight.

Thanks,
CC </div></BLOCKQUOTE>

You need to try again

Camelot Camper · 02-09-2008, 06:12 PM

Got both filters changed per Cummins instructions that I posted earlier, but had to crank the engine for about 10 seconds after completing the priming procedure. Below is a photo from the 2007 Camelot Owner Manual.

CC

danes-on-tour · 02-15-2008, 08:41 AM

Hi again!

I have now replaced my primary filter and I have to report that it didn't go all according to plan.

I chose to put the filter on "dry". I then proceeded to prime the filters many times by turning on the ignition for 30 seconds and then turning it back off. After 7 or 8 times of priming I cranked the engine and it started immediately. However, after about 30 seconds the engine stopped and it would not start again.

Eventually, after another lot of priming, I took off the filter and found out that it was only half full. I must have used all the fuel in the pipes and then run out.

I then took off the filter again and filled it from a Jerry can. Primed the filters many times and tried to start. No luck.

I then called Cummins emergency tech support and was told the following:

<span class="ev_code_BLACK">
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. </span> <span class="ev_code_RED">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.</span>

During my talk with Cummins we tried to start up the engine, but I eventually ran my chassis batteries flat. (Yes Mama - I will now install the gadget that charges my chassis batteries when hooked up to shore power).

I then went and bought a charger in order to charge up my batteries. I connected this up, then had a stiff brandy and went to bed sulking.

Next morning the batteries was fully charged again. I primed the filters 4 times and started cranking. After 20 seconds the motor kicked in and ran perfectly. This now makes me an expert on changing primary filters I will have you all know!!!

In a 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. Makes sense to me and in the future I will definitely apply this method.

I have not yet changed the secondary filter but will have an attempt at this soon. I think I now know what to expect. I will keep a large brandy within reach just in case

The Great Dane

Camelot Camper · 02-15-2008, 07:49 PM

Yep, I can't believe the amount of fuel I poured in that primary filter to fill it up. And as long as you change it first and then run the engine, the secondary filter (that you're going to change after the engine run) will catch what you put in the primary filter. It doesn't sound like it's worth putting the primary filter on dry from what you posted.

CC

Andy M · 02-17-2008, 06:08 PM

I am a little unclear of, why you can't pre fill them both (primary and secondary) as long as you filter the diesel real good prior to filling these filters. If soo, I would think that I would have less of a chance in running my batteries down while doing this process.

Someone please explain in further detail. Thanks.

Route 66 · 02-18-2008, 02:46 AM

Cummins position is, you can't filter the fuel adequately manually. The second filter, filters the fuel better than any manual filtering attempt.

Running the batteries down is not an issue, unless your batteries need replacement anyway.

You don't crank the engine with a dry filter, you just turn the key on and off several times to let the fuel pump fill the filter.

After 3 or 4 times of that, the engine starts right up.

I'm at a loss to understand why folks insist on filling filters contrary to Cummins instructions, and risk the the chance of introducing contaminates into the fuel system.

Ecker · 02-18-2008, 03:12 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Andy M:
I am a little unclear of, why you can't pre fill them both (primary and secondary) as long as you filter the diesel real good prior to filling these filters. If soo, I would think that I would have less of a chance in running my batteries down while doing this process.

Someone please explain in further detail. Thanks. </div></BLOCKQUOTE>
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It needs to be filtered down to 5 microns. You can only see 40 microns, If you can't see it how are you going to know its clean enough.

FWIW A gain of salt is 60 microns