Cummins ISC 2004 filter like housing leaking

[ok-rver]

Looking up from under the passenger side behind the rear wheels and I see this metal housing that looks like it might be a old style permanent housing filter. The housing had liquid on it that could be diesel or maybe ATF. Have not pulled the rear bedroom access panels off to get to it. The attached picture is of a pulled engine without hoses. What appears to be the housing is in the center of the picture with 3 hose fittings on it's top, the housing with electrical connection and nut for tightening at the bottom. What am I looking at and can it be tightened or a new gasket installed? It is located above the starter at the flywheel end of the engine.

[JDCrow]

Looks like the lift pump ( its in the location you described). I haven't seen one so clean! This is what some (myself included) have bypassed with a FASS system. Some have commented they have replaced the gasket. 

I'm just going off the top of my head. You may have common rail injection, I cannot recall the cutoff dates for CAPS2 pumps. I'd have to look it up 

Edited November 18, 2021 by JDCrow
Thought of something to add

[cbr046]

I have a 2003 ISC with a leaky lift pump.  Only a few drips but definitely an issue.  If you crawl under the coach you might see fuel dripping off the starter housing. 

- bob

[Reka52]

You could try tightening the three nuts on top,you might get lucky and stop the leak.  It is the caps fuel pump

[Endeavor to RV]

Yeah, it is the lift pump for fuel. Mine was leaking a bit. I was able to tighten the 3 bolts on top from the bedroom access. 

I think I was able to find a gasket available somewhere, but it took some looking. I ended up not buying one. It would also be a lot of work to remove and reseal it.  A new pump is quite pricey, too. 

Just tighten the bolts and see how it goes.

[jacwjames]

The real issue isn't the leaking fuel but the potential to such air after the engine is started.  Air is a problem for the injector pump, on member of IRV2 just got a quote for ~$7K to have his injector pump replaced.

Short term fix it to tighten the 3 bolts on top of the lift pump, long term you could try replacing the gasket, replacing the whole pump, or abandon the original lift pump and install a different transfer pump like a FASS of Airdog

[ok-rver]

Thanks for all the replies. The picture was from a salvage yard take out engine and this might be a replacement fuel pump, never been run as it has the factory plugs in ports. Cumin of Tulsa replaced the accumulator on my fuel injection a little over a month ago. They ran the engine from a 5 gallon bucket with fluorescent die to check the injectors which were good and then checked the pump and found the leak at the accumulator. Guessing they used the pump for flow thru from the bucket. Cummins offered to look and see if it was something they missed at no cost. Problem is if a new issue, it's $100s per hour. I will check tightness myself and see what's up. My leak is more than a few drops.

[Cubflyer]

32 minutes ago, ok-rver said:

I will check tightness myself

What you have pictured and described is the 'classic' lift pump leak.  That lower housing is not like a spin on filter, it is the body of the pump.  The standard leak is between the pump and the housing (where the hoses attach).  The pump is held to that housing with three thru bolts from the top.  Try tightening them, do not try to 'twist' the pump body (tighter).  Jim J (JACWJAMES) has suggested the best and the real long term fix.  I had the same leak, I by passed the whole mess, housing and all, used a #8 or #10 union with a 1/8" NPT "tap" (to install a fuel pressure gauge) to connect the flex hose to the engine to the metal tube from the lift pump output to the secondary filter together.  Mounted a FASS pump and filter unit where the original 'Primary' filter (the one with the clear plastic bowl on the bottom) originally lived.  Added a return hose to the fuel tank.   

If I buy another DP, that FASS pump & filter system will be the first thing I install.

Ken

[JDCrow]

4 hours ago, Cubflyer said:

What you have pictured and described is the 'classic' lift pump leak.  That lower housing is not like a spin on filter, it is the body of the pump.  The standard leak is between the pump and the housing (where the hoses attach).  The pump is held to that housing with three thru bolts from the top.  Try tightening them, do not try to 'twist' the pump body (tighter).  Jim J (JACWJAMES) has suggested the best and the real long term fix.  I had the same leak, I by passed the whole mess, housing and all, used a #8 or #10 union with a 1/8" NPT "tap" (to install a fuel pressure gauge) to connect the flex hose to the engine to the metal tube from the lift pump output to the secondary filter together.  Mounted a FASS pump and filter unit where the original 'Primary' filter (the one with the clear plastic bowl on the bottom) originally lived.  Added a return hose to the fuel tank.   

If I buy another DP, that FASS pump & filter system will be the first thing I install.

Ken

I did this, but the smaller version, no extra filters