RIP CM2250, 2013, 800,000km 20,000 hrs

[amermextrucker]

WTH?!

I just had my fuel pump head installed at Haggai, this is worrisome. Although they told me mine was a PX. I smell fuel washed truck twice already ( injector tube blew) . No visible leaks while running leak down test.

[Rawze]

(04-22-2022 )amermextrucker Wrote:  WTH?!

I just had my fuel pump head installed at Haggai, this is worrisome. Although they told me mine was a PX. I smell fuel washed truck twice already ( injector tube blew) . No visible leaks while running leak down test.

maybe there is a leak in a return line somewhere?

[SquareOne]

(04-21-2022 )Hermjeji Wrote:  Confirmed it's the head leaking again. Exact same spot.

Just my luck, 1 year and 2 month old new fuel pump, head says bye. 40 hours later, reman head from cummins, says good bye too. Still can't get a new one, next one will be reman too... have to wait 2 days for it to be shipped from the states.

Just thought i'd let everyone know so you stay on your toes.

Keep an eye on it. Mine appeared to be leaking as well at that same location (and like you, I was pi$$ed). The wetness never got any worse after the first week so I assumed it was maybe some oil on the threads seeping out from assembly due to the heating cycles. I now have around a 100k miles on the reman with no other issues so far.

[SquareOne]

(04-22-2022 )amermextrucker Wrote:  WTH?!

I just had my fuel pump head installed at Haggai, this is worrisome. Although they told me mine was a PX. I smell fuel washed truck twice already ( injector tube blew) . No visible leaks while running leak down test.

That fuel smell seems to linger for awhile, even after being thoroughly cleaned. It seeps into every crack and crevice which is near impossible to get fully clean. It typically will have to wear off. Every heat cycle unfortunately will cause some fuel smell until it is all gone.

Keep doing thorough checks. If you're not seeing any visible leaks or new 'damp' areas, then I'm sure you'll be fine.

[Hermjeji]

FYI, the third fuel pump head from Cummins, also started leaking from the head. Pressure was maintained this time on the test, but have just replaced it for the 4th time in ~3 weeks.

[Rawze]

(05-04-2022 )Hermjeji Wrote:  FYI, the third fuel pump head from Cummins, also started leaking from the head. Pressure was maintained this time on the test, but have just replaced it for the 4th time in ~3 weeks.

that does not sound normal at all.

maybe your high pressure relief valve has failed in the shut position and it is allowing spikes with over-pressures?.

also need to ensure it passes an injector leak test with flying colors. if not then it could be combustion gasses back-feeding into the rail and causing excess fuel pressures. - just another theory.

[Hermjeji]

(05-04-2022 )Rawze Wrote:  

(05-04-2022 )Hermjeji Wrote:  FYI, the third fuel pump head from Cummins, also started leaking from the head. Pressure was maintained this time on the test, but have just replaced it for the 4th time in ~3 weeks.

that does not sound normal at all.

maybe your high pressure relief valve has failed in the shut position and it is allowing spikes with over-pressures?.

also need to ensure it passes an injector leak test with flying colors. if not then it could be combustion gasses back-feeding into the rail and causing excess fuel pressures. - just another theory.

I think you're right Rawze. I am now on head#5. It started leaking with loss of power. Is there a way to isolate the high pressure relief valve verses bad injectors, other than putting on the part and seeing what it does? Might be that both are bad also (i thought the high pressure relief valve usually fails if there's excessive loss in the pressure >4000 PSI in the minute, haven't heard of one being shut in the closed position).
I'm open to hearing all theories here as I dive into it. Won't be back home till Sunday/Monday so gearing up to go through it.

[Rawze]

maybe monitor the commanded vs measured pressures and see if there are pressure spikes?.

[Hermjeji]

(05-06-2022 )Rawze Wrote:  maybe monitor the commanded vs measured pressures and see if there are pressure spikes?.

See the test below, It looks like once it reaches peak command, it does spike up and down. The last spike was at key off. This is just at 700 idle with the leakdown test. It's obvious it fails the leakdown test. However, on the other 3 ISX's i have not seen this when doing the leakdown test, it fluctuates, but not this much. Even the old rail leakdown tests, they stayed at 28500-29000 psi, not jumping up to 30k and down like this.



I want to hook up to it when it's loaded and pulling to see how it data logs then (but that won't be till Tuesday/Wednesday).