Freightliner/Cummins ISB-02 3rd Fuel Filter

[dickandlois]

Thought I had posted this information, but apparently I did not. This filter has a 15,000  miles recommended replacement cycle.

The ISB-02 Series engine uses 3 fuel filters and many Freightliner or Cummings service centers are not aware of the inline filter located in the frame rail, just behind the rear axle in most cases on the drivers side. I know of one coach where it was found  on the passengers side though ! Many shops change 2 filters and the coach still has no power. Many shops want to change the lift pump and or the injector pump when the engine fails to operate properly and a fuel filter is allot cheaper then either of the fuel pumps 

Years used are from late 2002 to 2006 using the high pressure rail injector system. So it might be prudent to contact Freightliner using the last 6 digits of the Vin number like G44444.

The first Vin portion needed is going to be a Letter !!!

The attached file offers some help, but in most cases it requires a small tech and is hidden under wiring harness. It is black and about the size of a medium sized banana. So caring a copy might make it easier to convince the service center to keep looking, because that 3rd. filter is there if Freightliner says it is.

Rich

In-line_fuel_strainer_for_ISB02.pdf

[obedb]

Wouldn't bypassing the inline filter with a fuel line splice and going with two fuel filters be enough? Would save future problems.

[jleamont]

Rich, is that a screen for large particles, like in the top center of the photo?

[wolfe10]

Yes, it shows as a 104 micron screen.  Really there just to catch chunks, rust, etc.

 

[jleamont]

I wonder what is down stream that they are trying to protect from debris, one way check valve, in-line mechanical regulator, that is only on the ISB and not the ISC or ISL?

[dickandlois]

1 hour ago, jleamont said:

I wonder what is down stream that they are trying to protect from debris, one way check valve, in-line mechanical regulator, that is only on the ISB and not the ISC or ISL?

Joe, the first thing the fuel goes through after the inline filter is a the large fuel filter / water separator in most cases if not all of the 02 series, then the lift pump and on to the second filter. So it is kind of puzzling, but that bad boy has caused more then one shop to scratch there heads. Most of the coaches have been around 8 years old before things show up and I have a little bird in my head thinking that it has caused a few lift pump and injector pumps to be replaced. One was running North of its home state Georgia. The shop that it was towed to was certain it was a pump issue, but the owner insisted they keep looking for a third filter. When it was changed the coach owner said it was running better then he could remember.

Rich. 

[obedb]

Never had anything like that in my 18 wheelers. Primary was usually a large Racor Fuel Water separator with replaceable element and then on to the secondary. No wonder big trucks are so much more dependable than the toys that we drive. One more time/ is that inline filter really necessary? 

No response means that perhaps I am no longer welcome here? 

[wolfe10]

Byron,

Not sure no answer has anything to do with being welcome???

Freightliner Gaffney would be place to ask that question, as they were the ones who speced and installed it.  Since it cost Freightliner extra $$, I suspect they had a good reason for installing it.  Few companies spend extra $$ unless they feel it is needed.

And only with the ISB engine, do it would not be on your coach.

[huffypuff]

When I worked fleet, many of our dump trucks had this third filter.  Was really hard to get to and easy forgotten on driver side cab over design front engine.  We knew it had it purpose and was caught with a few problems because of it.  

[jleamont]

14 hours ago, obedb said:

No response means that perhaps I am no longer welcome here? 

Byron, Welcome to the FMCA Forum! Sorry I couldn't resist . I was unaware you posted something and didn't get a response.

[manholt]

Byron.  On some of these post's things have a tendency to sometimes get lost...even people!  

Carl 

[jleamont]

Five, heads up you have that screen on your DD13. The filters in the photo above are from a 2015 DD13. Just in case you want to concur that on your own. The filter on the left is the factory fuel filter, the screen is right next to that (all are next to the cartridge oil filter) and the one labeled Detroit Diesel is a Davco, which I doubt you have but possible.

[manholt]

Joe.  FIVE would have a 2013 engine, since he has a 2014 Eagle.  Could be a 12 or 14, but I doubt that.

Carl

[jleamont]

34 minutes ago, manholt said:

Joe.  FIVE would have a 2013 engine, since he has a 2014 Eagle.  Could be a 12 or 14, but I doubt that.

Carl

The DD13 would be the same in those years, that engine has not been altered since its introduction with respect to the filter locations. large cap is the fuel filter, the small on toward the rear is the screen. The hand pump is between both.

[obedb]

Still don't understand why a motorhome needs three filters. Oh well?

[dickandlois]

Byron,

Maybe somebody thought the service centers needed more work! 

It does make one really wonder and I do not think we will get an answer.

Rich. 

[wolfe10]

Ya, the only reliable answer would have to come from Freightliner, Gaffney.  If there was a history of large chunks clogging primary fuel filters, that MAY justify a 104 micron pre-filter.

[cmarq]

When I worked for Cummins those filters were used to protect the primary lift pump which were like a automotive fuel pump. rust and debris would clog the valves.  They are usually are in the main line from fuel tank and do tend to be hidden and not readily accessible. 

 

[jleamont]

Ok, but what's different on the lift pump on the ISB vs the others. Supposedly they all share the same lift pump. Please enlighten us.

[cmarq]

They did use different types over the years, I retired 15 years ago so I don't remember all of them the old "B" used car type diaphragm pump. Later ones used a style that had check valves this was very susceptible to failures caused by debris. They have used electric lift pumps-- the feeling was they all needed protection from rust and debris. Just my own opinion but if the primary filter is before any pump they are not needed they were intended to protect the lift pumps that were before those filters. 

As has been mentioned before the truck or motorhome mfg. may think one is necessary.  The problem is Cummins makes the engine it goes to the end user and they decide what filters to use and where. Cummins gives recommendations but they may or may not be followed.  It created a lot of problems when I was a service manager when you tell a customer the oil pressure sender or starter, alternator, and other items were not supplied by Cummins and I could not warranty the part or labor.

[jleamont]

On the mechanical 12V engine that would be your primary filter. But on a 24V ISB the primary fuel filter is first inline. The only thing I can think of is they were trying to protect the oneway check valve at the primary fuel filter or it was oversight by the chassis manufacturer. I.e. just carried over from the 12v mechanical engine and forgotten about.

Cummins supplied my complete engine along with the fuel filters and housings. The only item in question is the alternator.  

[cmarq]

I don't know on the 24 v ISB,  Cummins does supply some engines with everything it depends on the order from the end user.  They also supply engines with no accessories the end user assumes that because it is engine mounted it came from Cummins,   Yours is easier for parts a Cummins service facility can look up parts by serial number. Things that were not supplied by Cummins they will have no info on.   I still get calls from people that knew me asking why can't Cummins tell me the belt number, for my alternator.