Cummins ISB-02 Fuel Filters/ Freightliner Chassis

[dickandlois]

This series engine/chassis was built from 2002-06 and has 3 fuel filters. There are 2 of them mounted on the passenger side of the engine when installed in a motorhome.

The first one (first from fuel tank) is the nasty one. It is located along the chassis frame rail - about the size of a banana. This fuel filter is located just behind the rear axle - inside the frame rail according to a Freightliner bulletin, but I know from talking to some coach owners it has been found on the drivers side behind the rear axle.

There have been other owners that have had issues with service centers missing this filter because they do not know it is there on many of the 02 series engine installations.

The first thing an owner of a motorhome built between 2002 and 2006 with a Cummins ISB-02 engine needs to do is contact Freightliner custom chassis with the chassis VIN number and ask if there unit has this third inline fuel filter and get the proper part number an a copy of the PDF file describing its location. Keep a copy with your information so you can provide prof of its installation.

The filter location is different on some chassis even though the file mentions only the drivers side for motorhomes.

The owners that have had issues with this filter have mentioned that the service centers have looked for it with little luck until a small service tech squeezes into the tight space behind the real axle near the engine and looks VERY Closely - over time it looks just like the frame area in color.

At times the tech needs to follow the fuel line forward from the engine to find this very small filter that plugs up over time because of its 10 micron filter screen. This filter input and output is connected with threaded connectors.

Good luck with this one as it limits fuel flow and will limit power and finally stop all the flow. There have been shops that want to replace the other 2 filters, then the fuel lift pump and then the injector pump.

This is not only costly, but will not fix the problem !!!!!

Rich.

[jleamont]

Rich, thank you for the info. Do you know if the ISL equipped chassis is set up the same? I will be changing my friends coolant, coolant filter and fuel filters this weekend on his Tiffin. If the NE weather is tolerable (too big to fit into my garage).

I had him test his coolant on his new to him coach. Wow it amazes me how some people and dealers miss the basics. Check this out;

Chassis engine coolant;

PH, 6.5

freeze point, -10

Nitrate, 800-1200

Generator coolant

PH, 7

Freeze point, -34

Nitrate, 200-500

My guess is the coolant filter is the original (cant see it in the tight engine bay), the fuel filters look like it (the two in the engine bay). When I saw the PH I flipped and called Cummins for their coolant recommendation on the ISL and Genset (2004 MY). They recommended Fleetguard ES Compleat (blue label) which is ethylene Glycol based pre mixed.

The best is this was "Just serviced turn key ready to go".

[dickandlois]

lleamont, The ISB-02 is the only one I know of that has the in line filter, but a call to Freightliner C.C. with the coach VIN would cover that question.

One item that you might want to change if it is the OEM coolant is the thermostat,. with the numbers he got on the coolant; the material in the assembly might not be in the best condition and changing it at the same time you do the coolant could save issues over the next 4 or five years.

Think the temps are going up to the upper 40's to 50's around the end of the week in your area.

Rich.

Note-One Coach owner found the filter behind the rear axle on the passenger side. (On the strait trucks- the filter is mounted with a bracket near the oil pan ) Info. might come in handy if you work on a delivery truck with the ISB-02 !!!

[wolfe10]

jleamont,

Ya, those acidic coolant readings put him well on the way to purchasing a lot of new cooling system components-- particularly the radiator.

I am concerned about the Cummins rep's recommendation for a "pre-dilute" coolant. That either gives a well-less than 50/50 mixture in an RV or requires a lot of extra work.

The reason-- you have many gallons of residual water even with a complete drain-- the 5/8" lines from engine to dash heater core and the heater core itself. I always recommend concentrate. Then, after the final rinse (distilled water) add 1/2 system capacity in concentrate and just top off with distilled water.

Here are complete "best practices" for changing coolant-- time consuming, but VERY low tech: http://forum.dieselrvclub.org/index.php/topic,6653.0.html

[jleamont]

Brett, thanks for the link and I agree after digesting it a bit more. I changed my coolant last year with the same 50/50 premixed Fleetguard product but all of my levels were perfect (just a PM for me). I rigged up a air nozzle with a regulator and a gauge and blew out the heater hoses through the Aquahot and back and used a vacuum fill tool to fill the system so there was no air pockets, your statement was dead on, it was a project.

I was considering the same for this coach but I need to be sure as much of this is out as possible. I also have the Cummins Cooling system flush two stage flush product in stock https://www.cumminsfiltration.com/pdfs/product_lit/emea_brochures/LI33024-GB.pdf.

I keep this on hand for all of the Powerstroke diesels when the oil cooler fails and introduces Motor oil into the cooling system. I have considered running this through the system but if the system is weak this could make it worse.

He has no Aquahot system, just hoses up to the front for dash heat, do you think blowing it all out replacing the Thermostats and water pump would suffice?

I asked how it performed while driving since it was bought in LA and drove up to PA, didn't run hot or leak....yet that is.

[dickandlois]

Brett had some good thoughts regrading replacing the water pump and radiator. Think you might ask the owner if they plan any long trips and how soon.

They might have some shorter trips planed that would allow them to get some run time on the coach and to keep an eye on things.

Should they be planing a long trip right now, then they will need to make the choice(s) on just how much work would be prudent at this time.

Also, how many miles are on the coach? Might contact the previous owner for any records or who they used and what the shop was asked to service and if there was any warranty time frame that might help to off set the repairs. It never cost anything to ask.

The numbers you posted do suggest that items where ignored, but as you mentioned - how could the location really say the coach was ready when picked up on the West coast.

Reputable shops do not like bad feed back. Unhappy clients spread there thoughts faster then happy ones !!!

Rich.

[jleamont]

Rich, no long trips that he told me about anyway in the near future, no short ones planned until late March.

The unit was purchased in Louisiana and it is a 2005 with 65,000 miles on it. He purchased it from an RV dealer, although they do not appear to be a Tiffin dealer they do carry new DP's of other lines. Now if they service them or not is always a crap shoot and it was purchased as-is. Probably worth a phone call at a minimum.

I guess its the old "buyer beware".

[bm02tj]

jleamont,

Ya, those acidic coolant readings put him well on the way to purchasing a lot of new cooling system components-- particularly the radiator.

I am concerned about the Cummins rep's recommendation for a "pre-dilute" coolant. That either gives a well-less than 50/50 mixture in an RV or requires a lot of extra work.

The reason-- you have many gallons of residual water even with a complete drain-- the 5/8" lines from engine to dash heater core and the heater core itself. I always recommend concentrate. Then, after the final rinse (distilled water) add 1/2 system capacity in concentrate and just top off with distilled water.

Here are complete "best practices" for changing coolant-- time consuming, but VERY low tech: http://forum.dieselrvclub.org/index.php/topic,6653.0.html

I believe it is best to mix water with the antifreeze before installing it in a 60 to 70% then top up with water as pure antifreeze can and will destroy the water pump seal if enough water does not get mix with the antifreeze when you start it back up

[wolfe10]

I believe it is best to mix water with the antifreeze before installing it in a 60 to 70% then top up with water as pure antifreeze can and will destroy the water pump seal if enough water does not get mix with the antifreeze when you start it back up

We are talking about a couple of minutes, as you refill the system, between adding coolant vs distilled water.

Without the extra work of taking loose the dash heater hoses (and motor-aid water heater if equipped) and blowing them out, concentrate is the only way to end up with a 50/50 mixture.

I have no issue with doing it either way, but many do not insure that the system is completely drained, and still use the pre-dilute. That guarantees for the life of the coolant that they have a less than ideal coolant mixture.

[five]

Chassis manufacturers build their chassis totally differently. My last MH was on a Spartan. It had a filter bay, last bay curb side. I could sit on a stool and very comfortably change both engine fuel filters and the external hydraulic filter. Current coach, on a Freightliner, has no filter bay. I can't even see the fuel filters, much less change them.

[jleamont]

Serviced my friends Tiffin yesterday. Brett, the thermostat looked like new, I was pleasantly surprised given the PH levels. I replaced the thermostat and all antifreeze, changed the chassis oil and filter and replaced both fuel filters.

I will say that coach was not built for engine bay access. It was tight and the rear doors are much too small. I guess I am spoiled with the Monaco design I have. The fuel filters were in a bad spot and difficult to remove once unscrewed, even harder to reinstall with the hydraulic hoses pressing up against the fuel separator. The fuel filters were so old they were rusty and the paint on the separator was falling off in my hands. I was surprised it ran so well.

To my surprise his ISL did not have a coolant filter, even though his engine serial number calls for it the manifold was not there. Another odd thing the valve cover is black along with the entire engine and all of the engine paint is peeling, all of the other Cummins engines I saw in those years had a red valve cover, later years the entire engine was all red.

On to the generator next, air dryer, axle and transmission in the weeks to come, weather permitting. It's back home in his driveway sitting until the next decent weather weekend.