Repeating CAPS Failures - Need Help

[Dr4Film]

My SilverLeaf VMSpc display shows variable oil pressure.

The guys at SilverLeaf should be able to help you.

Dr4Film ----- Richard

[dons2346]

Originally Posted by Dr4Film

My SilverLeaf VMSpc display shows variable oil pressure.

The guys at SilverLeaf should be able to help you.

Dr4Film ----- Richard

Mine did too until I had the sender replaced. Back in my range of engine serial numbers, Cummins had some bad pressure switches. It was a case of possibly failing in 500 miles or 5,000 miles or maybe longer. Mine made it until about 130,000 and then went south. Cummins, when this was all happening, came up with the solution of a static switch, either open (no oil pressure) or closed (55 pounds pressure) and this is the switch I have. I show 55 pounds anytime the motor is running so the gauge is worthless.

[bneukam]

Yep, mine shows 55 all the time as well. PO had it go out on him at 62k. Going down the road then everything just went dead. Had to have it towed into Cummins.

[rodney13]

Did you have any check engine light at the time it stalled ? Do you know what fault codes were logged ?

[dons2346]

Originally Posted by rodney13

Did you have any check engine light at the time it stalled ? Do you know what fault codes were logged ?

I was in a campground trying to air up the system and got a check engine light and it immediately shut down, I don't remember the code. I called Kevin Waite to see if he was in the Palm Springs area but he stays north in the winter. Told me to call Butch in FLA, so I called. After a couple of minutes Butch said I had a bad pressure switch.

Bad part was the coach was so low to the ground, there was no way to get under it so on the hook to Colton Truck. New switch and conversion harness was about 40 bux.

[gmgr]

Dropped MH at body shop for some work after 1300mi fall trip to visit family.
It 'visited' that shop til January in MN. The check engine light came on when I started it to leave shop. The engine died, but did restart. From there I limped to the truck shop that has done work for me. Life happens (husband illness) and it is still there.
They have done their troubleshooting... changed filters, there were no active ECM codes... took out for test drives, but on 2nd time out it had to be towed back in... the fuel pressure code activated... - fuel pressure sensor in accumulator was replaced. After test drive, got 456 fault code. Back in shop and found turbo condition ok, (low pressure)transfer pump is leaking. Before anything else can be done they are telling me that this needs to be replaced. Per Shop: "the first item to replace is the low pressure pump, which we know is slightly leaking fuel. My concern is that the low pressure pump has starved the high pressure pump and damaged it. To replace the low pressure pump, we will need to remove the starter to access it. I’m guessing the time to replace the low pressure pump will end up being 4-5 hours ($420-$525 in labor), and the cost of the pump is $440.77. "
So here I am.... following this thread to learn what I can. I know that the pump is expensive ($4-$5K + labor). To avoid the awful CAPS repeat that this thread follows, I requested both fuel and oil analysis. Just received with no action required.
It will be a hardship if I have to replace both lift pump and CAPS. To mitigate things, is it wise to replace with the FASS, hoping that solves the problem... how should replacement(s) be done so as to minimize the overall cost ? Your experienced comments are most earnestly appreciated.

[MnTom]

You may be fine repairing the old system or you may want to think about an upgrade such as a FASS pump. They are much more reliable and capable that a stock system. Fuel supply seems to be the key to longevity of the injection pump.

[jimmy braden]

I would start with a fuel additive, especially if you don't plan a large number of miles in the next few seasons..

[Smitty77]

First on the Lift Pump replacement vs FASS. No right or wrong answer on this, just different view points on how an owner defends the life of the CAPS!

The Lift Pump does it's duty at engine start up, and then shuts own, with the CAPS then taking over the duties of drawing/sucking the fuel thru the filters and eventually into thru the injectors so that combustion can take place. A leaking Lift Pump is not a long term positive condition to drive with. But, if the engine is starting the CAPS is doing the work after that, so while not a great thing for diesel to leak from the Lift Pump - it would not be an emergency type repair.

Specifically on the Lift Pump vs FASS. Well, I like the FASS due to the positive fuel pressure feed to the CAPS at all times. And I went ahead with the FASS as preventative maintenance.

But, set this aside for a moment. And review what this shop is doing. Seems like they're throwing parts at a problem, hoping that one of them will 'fix' a problem. Your symptoms described, are probably not related to a Lift Pump leaking.

Unless you have a long history with this shop, and trust them, perhaps you should look into another repair facility. Check RVSERVICEREVIEW for Cummins shops in you region. Ask here on the board for recommendations for shops in the region. Call Cummins to ask for their recommendation for a shop in the area. Heck, maybe even a Cummins shop is a reasonable distance away.

Maybe I'm trying to read too much between the lines on what you posted. And admit that sometimes finding/fixing Root Cause of a problem can take time. So perhaps I'm not being fair in my concern about wanting to now replace your Lift Pump - and not having any information for you on what is the real engine failure causing problem??

Could be money well spent moving to an Authorized Cummins repair facility (Regardless of if this place is classified as such.) - and getting a second opinion/fresh look at your engine...

My apology to you if this is a shop you've a long term relationship with, and or, a highly reputable shop. (And yes, a leaking Lift Pump should be considered a potential safety item. But many have driven for thousands and thousands of miles on slight leaking Lift Pumps.)

And a final comment, I'd second the recommendation on a Fuel Additive for that era engine on ULSD. I use Optilube Summer Blend most of the time for added Lubricity and Cetane.

All my best to you,
Smitty

[gmgr]

Thank you !..... (I'm thinking.....)
There are 118Kmi on the engine. The shop has had it running outside without an issue, but yet when driven a short distance, engine dies. It has been towed back in twice now. Shop tells me I should be able to drive it the 20mi home, but I'm uneasy about driving it anywhere.
I would think that there should be a code on ECM indicating the bad CAPS after the engine has died ? I'd hate to spend $7K on replacing the fuel pump, when there ause was an easy(ier) problem (air leak, etc..)
Is it possible that putting in the additive would solve the problem ? yay ??
I've dropped $1500 here so far.
Next step,... will follow your advice and check in with Cummins for possible 2nd opinion shop.
Will gladly accept any other comments, thoughts -- truly appreciate having a place to 'work through' problems.. it helps reduce stress level and helps in the plan of action that will hopefully reduce overall cost too. THANKS !

[TR4]

If your lift pump is leaking, you know you have to replace it. Now, you can replace it with a stock pump or install an aftermarket pump like the Fass. If your old pump is leaking fuel, then the CAPS is drawing in air after the lift pump primes. The shop won't be able to get an accurate reading on the CAPS gear pump if it drawing in air. I would fix the lift pump problem first with a new or aftermarket pump. I've been happy with my Fass pump Smitty recommended. I also use Optilube.

Bill

[gmgr]

"If your old pump is leaking fuel, then the CAPS is drawing in air after the lift pump primes." - but Smitty says after prime, lift pump shuts down ?
I realize the lift pump (with slight leak per the shop) needs to be taken care of, but if there is a 'very' likely possibility that the cause of engine shut down could be less costly than a new CAPS, I'd be 'for' finding that first, and then dealing with the lift pump as soon as funds become available (there's always the cash-flow issue; just purchased all new batteries and back 4 tires-need to do steer wheels soon).

[Dr4Film]

If your lift pump is leaking chances are there are codes that have been registered in your Cummins ECM which can be read by a Cummins tech using their Insight program. That's how a tech discovered that my lift pump had been leaking due to the number of specific codes in regards to the CAPS unit.

He went looking as to why there were so many codes and found the lift pump leaking but the diesel never hit the ground which would have alerted me to a problem.

You may even learn some other insightful stuff about your engine once they read the ECM.

Dr4Film ----- Richard

[TR4]

Originally Posted by gmgr

"If your old pump is leaking fuel, then the CAPS is drawing in air after the lift pump primes." - but Smitty says after prime, lift pump shuts down ?
I realize the lift pump (with slight leak per the shop) needs to be taken care of, but if there is a 'very' likely possibility that the cause of engine shut down could be less costly than a new CAPS, I'd be 'for' finding that first, and then dealing with the lift pump as soon as funds become available (there's always the cash-flow issue; just purchased all new batteries and back 4 tires-need to do steer wheels soon).

Gmgr,
I'm not saying you have to replace your CAPS. I'm saying, if your lift pump is leaking, your probably pulling air into fuel system. Smitty is right, the lift pump shuts down after prime and the CAPS gear pump takes over. Please update us on how your problem is resolved.

Originally Posted by Dr4Film

If your lift pump is leaking chances are there are codes that have been registered in your Cummins ECM which can be read by a Cummins tech using their Insight program.

Dr4Film ----- Richard

Richard,
My lift pump was leaking and did not throw any codes.

Bill