Repeating CAPS Failures - Need Help

[ColoradoHRE]

Originally Posted by Smitty77

I wanted to update that we've finished our first year with the FASS bypass of the Lift Pump. We just finished a 6 month trip of 8K miles, and had about 2.5K miles already on this mod.

All is working well. Due to some ECM Re-flashing, and replacement of the Fan Control Unit with the Source Engineering Thermal Valve mod, and a set of new tires with less improved Rolling Resistance - I cannot tell what caused our 1/4 - 1/3 MPG improvement over these last 10K+ miles. (And for sure, it could have just been the luck of our travels this year.) But my manually calculated MPG, adjusted for Generator and Hydro Hot usage, reflects this consistent improved MPG.

More power? Well not anything to say is pushing me back into the seat, and same factors above, but between all of the mods I feel we are able to pull long hills grades without engine working as hard. We can now pull one grade we know well in 4th gear, vs having to drop to 3rd before. (Just barely, but it is pulling the grade in 4th!). I suspect most of that is due to the fan running at only the RPM needed to maintain temperature. Where as before, it was jumping from Low to Medium, for most hill climbs, with about 1/4 to 1/3 of the longer grades, it would jump up to High speed off and on while climbing. So with the S.E. Thermal Valve, it is RPM wise consuming less power then the OEM set up.

I did not add a Fuel Pressure gauge. Thought about it, but my thoughts were that we'd had a 11 year old coach at that time, and the CAPS had sucked in the fuel in such away that I never felt we had a fuel delivery problem. With the FASS providing positive fuel flow at all times, I could not see it being any worse then the OEM setup. We have no inline fuel filter, and I maintain our Two Fuel Filters regularly. Yes, I suspect that a Fuel Pressure gauge could give me early warning of a bad batch of fuel, via gradually lower fuel pressure. But, decided to not add more components into the mix at the same time. For now, I'll keep running without it...

This thread covers the reasons for doing the added FASS (And or other companies products.). But just a reminder that for me, it was to do preventative maintenance on the Lift Pump. Ours was OEM, and I did not want to be on the road and have a trip delayed, and unknown group of mechanics, need to replace the Lift Pump. I'd also known coach owners that were on their second, and or third Lift Pump (Though I believe the newer Cummins Lift Pumps should be a more permanent fix.). Finally, the CAPS which is soo pricey - is both lubricated and cooled by fuel flow. This is why I went with the FASS, and bypassed the Lift Pump.

Long post, to say all is well, and I would change nothing on how Brazel's installed this unit on my coach. Very pleased.

Best to all, be safe, have fun,
Smitty

Update about actions taken - From ColoradoHRE

Fuel tank failed test that was done by Cummins. Denver was where test sample was taken and failing results are posted in this thread.

Did trip to Tetons with several fueling places and put on about 1,000 miles. Had another fuel sample pulled on return and Cummins Denver lost the sample which took about 5 weeks to find that out for sure with them finally trying to recover the data from their data base without any luck. They then pulled another sample and got passing results in about 2 weeks so the $1600 dollar cleaning and our normal fueling stops on the Teton trip gave us a passing condition for our fuel tank. So that was a positive result in the one identified area that may have been the root source of CAPS fuel pump failures that we have experienced. Note: No guarantee that was the failure root cause but definitely was an identified item that could cause failures.

Summary of other actions we are doing:
1. We are using a lubricity additive with every fueling and will continue to do that as long as we use the coach. Thanks to forum suggestions for this.
2. We are going to inspect the fuel bowl frequently on the 1st fuel filter for any signs of contamination - visible particles and water. Will change both filters on a short usage period or before any longer trips.
3. Tried to get a restriction measuring installation from Cummins Dever but they spent a little time trying to come up with the design and then did an about face and said they would not do that as it would require a 3rd party part and they will not do that. Said that there are diesel shops in Denver that would probably do that kind of installation.
4. Did not do the full time lift pump that Smitty77 and some others followed his lead and had tentatively decided to just go with a restriction monitor to identify fuel starvation conditions. I am reversing that decision and am going to call the installation place that Smitty 77 used for some guidance in making that modification to the CAPS fuel system.. I would also like to have a restriction monitor in addition to the full time lift pump but I will need to find out from them if that can reasonably be done. Obviously I am very disappointed with Cummins Denver for not being willing to do anything towards helping a customer that is having a series of failures with a Cummins engineered fuel system and is known to be a vulnerable system.

I plan on continuing to update this thread as I pursue the full time lift pump and any restriction measuring system. Thanks to each one that has contributed to this thread and hopefully the posting will be of some help to others that have experienced the same problems or similar problems.

Regards, ColoradoHRE

[jleamo1]

I also changed my system to a positive flow rather than suction utilizing a Fass pump. I went a bit over board, I put my pump at the fuel tank with a Davco primary filter before it, one way check valve at the tank and a fuel pressure gauge on the dash with the sending unit after the last filter before the fuel injection pump. So far I have accumulated a little over 1000 miles and while I have only owned this coach for 2.5 years it has never ran this good! My OEM lift pump and fuel lines were replaced just after we purchased it in May 2014. I was told by a local fuel injection pump shop that the Injection pump on the ISL,ISM will take positive fuel pressure, what it doesn't use it will just return to the tank.

[jleamo1]

gauge in the dash

[ColoradoHRE]

Originally Posted by jleamo1

gauge in the dash

Thanks so much for the posting!

Wondering if you would give a brief description of the 2 photos of your mods?

Also about the install process and who did it and where? I can do quite a bit of install stuff but I think our HR Endeavor does not have the type of access that I think your system has if I am interpreting the photos correctly so I am probably going to have to find a place that has more experience and skill than I have to do the mods. We are reasonably close to Denver so that may be where we can find a business that can do this type of work.

[jleamo1]

I did the install myself. If you start at the beginning of this post there is a description of how others have done it. I went a bit over board and reengineered the entire fuel delivery system and put the pump up front at the fuel tank and of course when you do that you need to move the primary filter up front also, at that time I decided to go with a Davco primary filter so I could see when it was clogging. I have had problems in the past with bad fuel and I figured a quick peak rather than sitting on the side of the road would be beneficial to the fuel injection pump and my wallet. There is a company that has done a few of these but I believe they are in Washington State, Brazels RV link; https://www.brazelsrv.com/
It was a bit of a project and I worked on and off of it for a month all the while using the coach on its factory design.
The photo above if you look closely the fuel tank is just behind the filter and the pump is to the right of it.

[BRex45]

Jleamo 1

That is a clean looking installation of the fuel/water separator. Very nice work.

Could you say where you purchased it?


Thanks!

[jleamo1]

Originally Posted by BRex45

Jleamo 1

That is a clean looking installation of the fuel/water separator. Very nice work.

Could you say where you purchased it?


Thanks!

Thank you for the compliment! I bought the Davco from a Freightliner dealer, it actually fits a 2012 Freightliner M2 with an ISL Cummins engine. The filter inside has the same spec as the factory filter it now replaces.
I wanted to be able to see the filter condition rather than guessing at it. By design as the fuel level rises in the bowl the filter media is becoming more clogged, when the fuel gets to the red line on the bowl its time to replace the filter.

[mackwrench]

Most all new trucks are now equipped with only the Davco filter, no spin-ons.....depending on the Fleetguard element filters down to 25 microns. Very easy to replace element, no guess work on when filter needs changing.
It does take some getting used to as when you look at it it will not have much fuel covering the element, and looks like it's full of air.

Definitely a worthwhile upgrade.

DAVCO Fuel Pro 382

jleamo1, Did you leave the spin on filters on? They make a diverter cap that spins on in place of the filter if you want to do away with it.....

[jleamo1]

Originally Posted by mackwrench

Most all new trucks are now equipped with only the Davco filter, no spin-ons.....depending on the Fleetguard element filters down to 25 microns. Very easy to replace element, no guess work on when filter needs changing.
It does take some getting used to as when you look at it it will not have much fuel covering the element, and looks like it's full of air.

Definitely a worthwhile upgrade.

DAVCO Fuel Pro 382

jleamo1, Did you leave the spin on filters on? They make a diverter cap that spins on in place of the filter if you want to do away with it.....

I removed the primary and just connected the lines together, the secondary remains in its original location. I connected the fuel pressure gauge just after the secondary filter with a "T". The photo is from before the mod.

[RVingDutchman]

Wow this is some thread and I'm NOT very Exited to have to be a part of this but unfortunately I'm here under duress !!!
I am having serious fuel starvation issues and on my last trip stopped at a service place where they put the computer analysis system on and it showed several fuel related codes but He could not for sure tell me if it was the pre or main fuel pump???
That said I barely made it home and now have to decide what to do???
The Missus already decided she's had enough of this breakdown monster and does not want to go full time anymore but either way I could not sell it the way it is so something has to be done.

After doing a lot of reading and research and reading this thread very carefully (and it has been a great help guys) I thought of first installing the FASS pump and see is that would be enough to make it work properly and hope to the high heavens that there is not to much permanent damage to the fuel injection pump? Only then If it appears not to be the right fix to go farther and rebuild the fuel injection pump and inspect /repair the fuel delivery system.

Of-coarse I have in the weeks leading up to this done my due diligence in changing fuel filters (twice) and checking for leaks and other possible causes but not found any!!!!

I would love all of your input and suggestions, as I can not afford to make any big mistakes here.

Like my wife wants to park it on an acreage and live in it but not travel cause she loves it but is too afraid it will brake down every week.......

I love her to death but that just does not make any sense to me..... ???

Regards,

Ed

[RVingDutchman]

I forgot to ask one very important question, when ordering the FASS pump there are manny different models ranging from 95 to 250 GLN. per HR. (gallons per hour) Now that's a LOT of fuel to pump around and around and around +so on.... Personally I would think 95 GLN. is more then enough but what did you guys install and what was recommended ?????

My point is that when the tank is full its one thing to pump 150 GLN. around in an HR. (w.a. 150g/h pump) but when yr down to a 1/4 tank it does stir up the rest of that fuel an awful lot more and likely heat up the fuel a lot more pumping it through 80 ft of hose and all the equipment time and time again.
Just wondering what is really needed?

Regards,

Ed

[MnTom]

I suggest you contact FASS directly to get the answer to which unit to get. Welcome - Fassride

[RVingDutchman]

Originally Posted by MnTom

I suggest you contact FASS directly to get the answer to which unit to get. Welcome - Fassride

Could certainly do that, Sound advice !!!

Ed

[jleamo1]

Ed, Fass will guide you to the correct pump for your application. Everything else will be custom. Don't panic its really not that bad. I gave them HP and torque, they confirmed the pump model. I installed Fass part number FA D08 95G. This is the pump recommended by them for my HP/torque combination.


My biggest problem was as my primary filter would have the slightest blockage the coach would buck, and I mean slight blockage! I cut every filter open expecting something horrifying, never saw much to be concerned with and my lift pump and fuel lines were all new. The system was just too large with the distance from the fuel tank to the engine, drawing fuel through a 10 micron filter for that little factory pump (on the back of the CAPS pump)to manage, so I gave it some help. I figured if I didn't do something soon the CAPS pump was going to fail. The Davco seemed like a good investment as the trucks I was a custom to working on always had them.


Mackwrench, I bypassed the factory primary filter due to the check valve built into the inlet side of it. I put one inline at the tank now, so there is always fuel in the entire system rather then risking a dry pump situation.
Check valve part number; https://www.summitracing.com/parts/sum-220194b