Cummins 6CTA 8.3 fuel transfer pump

[BluewaveRV]

In buying a 21 year old RV-bus, I had no idea this would be a work in progress never ending.

I had tranny leak in my Allison 3060 about one of the filter covers.
Now the leak has left/stopped, moved to the co-pilot side like it is at the seam/pan mating surface gasket.....
I pressured sprayed the area & then rubbed in bar soap, since this will stop gasoline on a crack in a fuel tank, why not a transmission pan..... It did...
I feel that the lack of use maybe the trouble & seals are lacks......


I now have troubles with the 6CTA 8.3L engine.

I need to ask if anyone has replaced the Fuel Transfer (lift) Pump P# 3932224 in a 1995 HR motor home like mine ???

After reading many web sites on this, I seams like it could be a task....

I first have to pressure spray all the crud that has built up over the years & 77K miles with out getting spray-back into the bedroom. The FTP seams to be under a plate that supports the throttle. Having the sheath/housing of the cable mounted & other parts on this plate.... The whole engine & trany is dirty with caked on crud.....

Found the parts at Sumner, north of Tacoma WA. & Tim (425-235-3400) was so helpful & their prices were very near what I had found on the internet, I went with them & the FTP just showed up....

I had also ordered shop manuals on my 6CTA 8.3L 1995 engine too, will come in later..

The "Starting Aid" P# 3928188 is something that (maybe) Spartan had installed on the intake manifold, there are two of them, co$tly $165 units, & have to come from Belgium.

WHAT I HAD EXPERIENCED AS THE FUEL TRANSFER PUMP SLOWLY FAILED;
1) The quick starting that I really liked, changed to a lot of cranking attempts & increased in number. But engine had normal power.
2) Last trip (to see the eclipse in Idaho) the pump must totally failed, but did not stop flow of fuel. It got so bad that going up hills was getting questionable as to "will we make it" shifting down to 1st & only depress the throttle a small amount, for the engine would start losing power with more throttle.
3) By manually shifting on the flat, was able to get the RV up to 70 in Idaho on I-84, but the hills would take the wind out of the sails & force down shifting. Managed to limp home to Silverdale.
4) With RV on level or nose down was very hard to get started. But with nose high (gravity feeding injector pump) it starts on 1st attempt.
SO FOR ALL OF YOU THAT MAY HAVE THIS HAPPEN.... That Fuel Transfer (Lift) Pump that cost $95 & 1 or two gaskets @ $4 each maybe your troubles....
I apologize to all that I may have delayed in our travels 2 days after the 21 Aug Solar Eclieps going down Id-55 & getting off I-5 to HWY 101 to Hwy 3.

ANY THOUGHTS, HELP, OR ??? WOULD BE APPRECIATED.... John

[Skip426]

Welcome to iRV2.

First question .
Have you changed the fuel filters and checked the pump pressure ?
Because the symtoms you describe could easily be a plugged fuel filter.
Does the pump look like the picture below ?
If so in 14 years of Dodge/ Cummins repair , I can only remember replacing two of the mechanical lift pumps on the 5.9 mechanical pump Cummins .
The only trick is to make sure the cam shaft; fuel pump drive lobe; is on the back side , so you have minimal resistance to pushing the pump to the side of the block to start threading the mounting bolts.

[BluewaveRV]

Skip...
I was told from the seller he had changed out all the filters...
Maybe it is time to question that.
A fuel filter would be Le$$ co$tly & easier too....

QUESTION: Will there be fuel flowing from the filter mounting when removed??

By opening up the old filter, that will tell me if that is my trouble...
Thanks for your insight/suggestion.

[BluewaveRV]

Skip,
No filter change...
Have drained it though a few times.
Fuel pressure would be a niceaty to have a gage some where too.
Thanks John

[dmurdock]

Originally Posted by BluewaveRV

Skip...
I was told from the seller he had changed out all the filters...
Maybe it is time to question that.
A fuel filter would be Le$$ co$tly & easier too....

QUESTION: Will there be fuel flowing from the filter mounting when removed??

By opening up the old filter, that will tell me if that is my trouble...
Thanks for your insight/suggestion.

Some fuel may come out..have the new filter pre-filled and ready to install. I have the same engine and I pre-fill my fuel filters with ATF (transmission fluid). One issue you may have is that depending on the coach builder, you may have a fuel filter right next to that lift pump that is often overlooked. It's just a secondary filter but if it has enough gallons through it could be clogged/clogging. Mine is an absolute @$%#$% to get too.

[BluewaveRV]

Thanks for the feed back....

Why, ATF in the fuel filter & not diesel??

One of the reasons I have had as to why I had thought my trouble was a transfer/lift pump was that there seems to be a loss of a check-valve, & fuel drains back into the tank. Thus having to use the starter a great deal un less the RV's nose is high at witch the Cummins starts on the 1st try......

I have the pump & it looks very similar to your picture, only noted difference is a black rubber bellows that is over the hand/manual (I believe) plunger. pump portion of the pump.
It has been to hot to work on the RV & weather is going to cool some.
I'll get the information off the Filter, so as to get the correct one on the 1st try, I hope locally.
I have a copy from DieselServiceParts.com that calls out for the Cummins ISC engines made after 1998 that suggests a filter change every 15K miles & the number is FF5488. I need to verify that ## & it is not that east to see when parked on the flat.

Thanks for the come-backs, suggestions on this.
I welcome any thoughts all of you have... John

P S For all that are looking to cut power drain on house batteries, Look at E-Bay & you can get near any filement light replacement with an LED = CHEAP!!
There are two types of LED replacements though, both save power.
But the lights that have a small circuit board = PWM instead of a resistor will save the best (50% or more), but cost more too. Also consider replacing the old transformer-heavy type of inverter with the new step-type that will save a lot of wattage too. Note Microwave ovens do not like them though. TV & DVD players & other NON-Transformer-input electronics work great.

[dmurdock]

Originally Posted by BluewaveRV

Thanks for the feed back....

Why, ATF in the fuel filter & not diesel??

One of the reasons I have had as to why I had thought my trouble was a transfer/lift pump was that there seems to be a loss of a check-valve, & fuel drains back into the tank. Thus having to use the starter a great deal un less the RV's nose is high at witch the Cummins starts on the 1st try......

I have the pump & it looks very similar to your picture, only noted difference is a black rubber bellows that is over the hand/manual (I believe) plunger. pump portion of the pump.
It has been to hot to work on the RV & weather is going to cool some.
I'll get the information off the Filter, so as to get the correct one on the 1st try, I hope locally.
I have a copy from DieselServiceParts.com that calls out for the Cummins ISC engines made after 1998 that suggests a filter change every 15K miles & the number is FF5488. I need to verify that ## & it is not that east to see when parked on the flat.

Thanks for the come-backs, suggestions on this.
I welcome any thoughts all of you have... John

P S For all that are looking to cut power drain on house batteries, Look at E-Bay & you can get near any filement light replacement with an LED = CHEAP!!
There are two types of LED replacements though, both save power.
But the lights that have a small circuit board = PWM instead of a resistor will save the best (50% or more), but cost more too. Also consider replacing the old transformer-heavy type of inverter with the new step-type that will save a lot of wattage too. Note Microwave ovens do not like them though. TV & DVD players & other NON-Transformer-input electronics work great.

ATF seems to prime easier and it is already filtered (diesel isn't filtered).

You say fuel drains back into the tank..that's a new and very helpful observation. If I remember correctly there are two checkvalves in the fuel pump system and if either goes bad it will cause issue. Watch this video:
https://www.youtube.com/watch?time_c...&v=HhO_NWqkOcg

[MSHappyCampers]

Hi John! Welcome to IRV2! We're sure glad you joined the gang!

Congrats on the new rig! Sorry I can't help with the questions. I'm about as far from being a mechanic as you will ever find! Keep her between the ditches!

Good luck, happy trails, and God bless!

[veraken]

If you haven't done so already, get your ESN (engine serial number) and go to https://quickserve.cummins.com/info/index.html and register your vehicle. It's a great source for info on replacement parts. You can also call Cummins Customer Service 1-800-343-7357 and they will be able to help you. Sometimes, the info on other sites are not correct.

[BluewaveRV]

Interesting YOU-TUBE Video. I need to find a PC that has sound to play it on again.
Sure seem like the person handle the parts, is rough with them. I will assume that the pump will not be used again.
I have shop manuals coming too. They will help me understand just where, & what parts are. Would be great to place a Oil Pressure sender in the out-put of the pump with an other "Idiot Light" on the panel with all the others, or better yet a gage, even a LED Bar graph gage.
Electronics was my profession with GTE in equipment repair services + having my FCC-1st Radiotelphone license, & my hobby was flying & maintaining my Cessna 172, having earned my FAA-A&P licenses.
John

[Papa_Jim]

John,
If you have the new fuel transfer pump you might as well change it out. It's not too difficult to do.

Your secondary filter is located above the fuel transfer pump. A common error when replacing this filter is to miss installing the small o-ring on the threaded nipple before screwing the new filter on. In fact, sometimes this small o-ring is not included with the new filter. This can cause problems.

Your primary filter may be located at the back of the engine compartment. It's possibly on a priming pump which may have a glass jar. If it does, the seal on the glass jar can fail, allowing fuel to siphon back to the fuel tank when the coach is sitting.

In any event, I would change out the fuel transfer pump and the two fuel filters. It's a good place to start.

Hope this helps.

Jim

[BluewaveRV]

I sure wish to thank you all for your thoughts, experiences, & knowledge !!
There are many things that are not in manuals... Found that in maintaining my Cessna 172 over the last 31 years...
I hope to see the shop manuals that I have bought come soon & add all your suggestions as to what I need to look for & do.....
I have noticed some type if ??Leak?? that has cleaned off an area of blue wire bundling between the injection pump & where I believe the transfer/lift pump is but lower & just above the parting of the engine oil pan. Access to the engine was made very difficult by previous owners attempt to make a hidden area. I have now changed that back, added wedge-support to raise the head of the mattress 5.5 inches & allows total lifting of the cover over the engine, dirty,dirty engine... Where I have found other troubles I'll have to bring up, once I can figure how to post pictures in these "threads, Quick Reply, & postings.. TKS John

[dmurdock]

A fuel leak could definitely be the problem as if fuel can come out air can come in. I've been hesitant to post in fear of leading you astray but I really doubt your issue is the lift pump..it could be but sounds way more to me like a bad check valve (which there are two in the lift pump and one on the injector pump) or a place before the injector pump that is allowing air to be sucked into the system. Get it clean and cover it with baby powder..you'll find the leak.

[BluewaveRV]

YES !! There is a filter just above the Lift Pump & is going to be a #*@%X to get to with that plate that holds the sheath of the throttle, cruise control to injector pump & a solenoid that controls ?? Fuel shut-off?? I do not know yet.
I bought the shop manual & it appears to be worth the $75 & explains in depth remove & replace & How too rebuild the Lift Pump.......
I find this filter close to the lift pump to be an after-thought....
Who thinks (??) of this location, next to impossible to change from below or from above?? A neighbor showed me the two filter + electric lift pump after-market unit he placed in his 4x4 Dodge dully. That is impressive in that both filters you can place both of your hands on & offers an other method of anti thief with a hidden switch.
I'll get my "Bore-scope" out & look for the filter numbers, I want to have them at the time I need them.
Going to clean this engine 1st, Turn on the roof-top blowers & slightly pressurize the interior & use compressed air blow off all the dirt that is loose enough & then use my 1700 psi pressure washer to clean off the "caked-on" dirt, oily deposits......
This is where I like working on airplanes... their clean !!
Thanks again !! John