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Florainer · 05-14-2021, 05:09 AM

Our 2003 Holiday Rambler Imperial (RR8S chassis) has an ISL 400 engine. The engine manual only gives the part number for a single fuel filter, but our rig has two fuel filters. The manual calls for a Fleetguard FS1022 (10 micron), which I assume would be for the secondary filter. But what should we use for the primary filter? The Roadmaster chassis manual doesn't give a part number for this. Thanks for your help with this!

TGAWLAK · 05-14-2021, 05:33 AM

on my 2004 Monaco Windsor 400ISL the fuel filters are Fleetguard FS1003 and FF5488 I buy them online and delivered right to my door I just keep a pair on hand. Sometimes the manuel numbers are not correct

Florainer · 05-14-2021, 06:53 AM

TGAWLAK - By your saying that sometimes the manual numbers are not correct are you saying that the two Fleetguard part numbers you listed didn't come from your manual? If so, or in any case, may I ask what the source of those numbers to be used with your rig was? Thank you!

TGAWLAK · 05-14-2021, 07:01 AM

when I purchased the coach the service center did not have fleet guard filters so the crossed them to carquest filters but as I do my own service I crossed them back to Fleetguard and yes the manual states the numbers were correct at the time of publishing but in my case the numbers were different

TGAWLAK · 05-14-2021, 07:12 AM

The manuel says at the time of publishing the numbers were correct but it my case they are different I did order the numbers out of the manuel but the filters were incorrect that is why I crossed them back to Fleetguard

wolfe10 · 05-14-2021, 07:28 AM

Best advice: Call Cummins with your engine serial number and ask what micron rating your final fuel filter should have.

Then choose a courser element for your primary fuel filter.

Example:

Somewhere between 10 and 30 micron primary.
5 micron secondary.

Ljwt330 · 05-14-2021, 08:26 AM

MY Cummins ISL 400 engine is likely just like yours. As a CAPS engine, it had one filter, the Fleetguard 1022 which is also the fuel water separator. It is rated at 10 microns. This filter is the first (and only) filter in the system and plumbed after the lift pump, but before the CAPS pump. The High Pressure Common Rail fuel injected engines came out with the 2004 builds, and they typically had two filters.

If the coach builder installed a second filter, it can be of any spec they chose. Point being, Cummins calls for one 10 micron filter as adequate. A second filter may be better, but you need to be aware of fuel flow restrictions as the second filter becomes clogged, given that it is a smaller micron filter. Starving the CAPS pump of fuel, causing cavitation, air in the fuel, and loss of cooling, will rapid kill the pump. Keep in mind, the CAPS pump must pull the fuel through the plumbing, it is not a positive pressure set up. You want to avoid making the work of the pump more difficult.

Word of caution about cross-references. I tried to get a filter for my engine while on the road, the Fleetguard 1022. NAPA had their brand, a high-quality "NAPA Gold", that cross referenced. However, their filter was 4 microns. I passed.

You may need to find the part number on the secondary filter itself, if you cannot track down who installed it.

96 Wideglide · 05-14-2021, 10:11 AM

Quote:

Originally Posted by Florainer

The manual calls for a Fleetguard FS1022 (10 micron), which I assume would be for the secondary filter. But what should we use for the primary filter?

I believe the way it works is, if the part number begins with 'FS' it's a fuel separator, therefore primary filter, and 'FF' is fuel filter, or secondary.

On your ISL, 10 micron is standard for primary, 5 micron secondary.

Florainer · 05-14-2021, 11:38 AM

I've finally found what I feel is a reliable answer to my question. I called Lazydays in Wildwood, FL (they were Alliance before Lazydays recently bought them, and Monaco's factory-owned shop in Florida before that. Many of the employees have been there a long time), and was told that the original setup by Monaco for my rig was the Fleetguard FS1022 for the secondary filter, which is what the manual calls out for the (single) filter, and a Racor S3201P for the primary filter. The S3201P crosses to a NAPA FIL600212. Both the S3201P and the FIL600212 are 30 micron filters, that use the clear plastic bowl on the bottom. When we took our rig to Cummins in Syracuse, NY they installed a Fleetguard FS1212 for the primary filter, which is what Fleetguard crosses the S3201P to, but the FS1212 is a 20 micron filter without the clear bowl on the bottom. We had just bought the rig (used) then, and I don't remember what primary filter it had when we got it, but someone along the way switched the rig away from the original configuration, and threw the plastic bowl away in the process. So now I've bought a Racor S3201P from Diesel Filters Online, and an equivalent to a RK30475 plastic bowl assembly (made by Marpac) on eBay. Oh, and a Fleetguard FS1022 on Amazon. Too much detail? Sorry! I'm just hoping this helps some other Monacoers. Thanks!

P.S. The Ohio shop put a 14 micron filter on as the primary (should have been 30), and a 2 micron filter on as the secondary (should have been 10). Too easy to clog up, I would think. Monaco and Cummins chose the 30 and 10 for a reason.

wolfe10 · 05-14-2021, 11:42 AM

Quote:

Originally Posted by Florainer

The Ohio shop put a 14 micron filter on as the primary (should have been 30)...

As long as the primary is quite a lot courser than the secondary, I don't think there is a specific "primary MUST BE XX micron).

So, yes, I agree, if 10 secondary is Cummins spec, I would like to see a wider spread between primary and secondary.

shootist · 05-14-2021, 06:24 PM

Fs1022 and fs1212 fleetgaurd are what my 2004 uses. One on the right has water sensor in it.

96 Wideglide · 05-14-2021, 06:53 PM

Quote:

Originally Posted by TGAWLAK

on my 2004 Monaco Windsor 400ISL the fuel filters are Fleetguard FS1003 and FF5488 I buy them online and delivered right to my door I just keep a pair on hand. Sometimes the manuel numbers are not correct

Believe these are the part numbers in my manual as well.

I just cross reference these to Donaldson filters, as they are easily accessible to me.

Lowflyer1 · 05-15-2021, 06:41 AM

My 2004 HR Imperial with CAPS pump:
-Primary FS1242 (filter only, FS1242B has clear sediment bowl included), 20um.
-Secondary FS1022 (has water in fuel sensor), 10um.
I got 6-pacs of those from Amazon, so don't need to worry about running out of filters any time soon.

On mine also a previous owner had gone to different brand filters, primary without sediment bowl.

Florainer · 05-16-2021, 11:31 AM

Ljwt's word of caution about cross-references should be a lesson to us all. In my case Cummins cross-referenced a Racor S3201P to a FS1212, which resulted in my losing the sight bowl and going from a 30 micron filter to a 20 micron filter. This change was installed at a Cummins service center, with no notice to me of the changes. Then the next shop that did an oil change crossed the FS1212 to a Wix filter that is a 14 micron one (Wix's website crosses the FS1212 to two possible "equivalents", both of which are 14 micron filters. And that shop, per Wix's cross-reference, replaced the FS1022 secondary filter with their P/N 33422, which is a 2 micron filter instead of a 10 micron one. And again the shop did not tell me of the changes in the filter specs. So RVers better double-check the specs of these filters, and not rely on the manufacturer's claims that they are equivalent.