Community Forums

Full.Monte · 09-22-2014, 12:32 PM

I'm looking for the correct part number for the in-tank fuel pump on my rig.

It's a P32, as in the signature below. Model P31832. Last 8 digits of the serial number are 23353669. Chassis number is 5B4LP57G32335. Manufacture date is May, 2002 for the chassis. Motor home year is 2004.

I have the following part numbers from a web search, but don't know if they match the MH I have:

workhorse 25315352
workhorse 25178125

Thank you for any help!

garyspang · 09-22-2014, 08:47 PM

My "Serial Parts Book" for Model P31932, Build date May 30 2002 and VIN 5B4LP57G633359077 identifies it as " O/E Part Number 25178125, MODULE ASM - FUELTANK FUEL PUMP (WITH SEAL)".
It is illustrated here OEM 25178125 Fuel Pump Module Assembly | Frugal Mechanic

I replaced mine at about 75,000 miles. Then it failed again and only delivered 17 psi. I suspect rust abrasion from the ethanol sucking up water causing fine tank rust. So I installed an external in-line fuel pump from JEGS High Performance with a filter before and after the pump, so I would not have to take the tank down again. A real pain because workhorse originally tightened all hose clamps from the top and only bottom access is available. Luckily enough extra was available for a one time hose cutting at the tank nipples. Beside an annoying high pitch pump whine at the exterior, the external in-line fuel pump has been working great (now at 130,000 mi).
If you do take down the tank, lube all hose nipples with plumbers silicone grease for easy insertion and second removal without cutting.

Full.Monte · 09-22-2014, 09:13 PM

Thank you for a very informative reply! That will be very helpful. Thanks again!

aldevinaspre · 09-23-2014, 12:28 AM

I would like your part number for the external fuel pump. My in tank quit in Hawthorne Nev. last August. I had no choice but to buy the Delphi from Napa. Quit on Thursday and couldn't get it until Sat. Ran the generator all the time to empty the gas tank. This stuff never happens at home, only in the least likely places, and of course a person doesn't have all the tools with him to drop a gas tank. It would be nice to have a spare just in case. My mileage is about 60,000 and the pump was $470.00 I had the wife, 5 kids and a dog with us. At least the garage had wi fi so the kids were occupied. Also, if anyone has the Delphi, I would like to know the Ohms of the sender. The orig is about 250 ohms. Thanks for any help!
Aldev
2002 32 H Bounder W22
Torrane Ca.

TAN · 09-23-2014, 09:03 AM

I paid $1200.00 to have mine replaced in Las Vegas. This was about 5 years ago.

garyspang · 09-23-2014, 01:06 PM

FULL.Monte
I was not successful removing the fuel line special fittings so I had to cut the three plastic nipples on the pump with a hack saw then remove the hoses from the fitting stubs.

Hi ALDEV
I will get the information for you and crawl under the MH to take a picture for you showing the installation.
Hopefully by the end of the day.

garyspang · 09-23-2014, 07:54 PM

Hi
Well, I crawled under the MH and took pictures. You owe me a coffee. The Jegs.com order number is 555-159001 and it cost me $151.99. You still need a long length of fuel tubing with O-ring end fitting, a length of fuel hose, two fuel filters, Fuel filter fitting with barb, hose clamps etc. I don't remember all the detailed parts, since the pump was installed in March of this year.
The entire installation is protected by a shiny aluminum heat shield. It is placed in the same area as the fuel filter location inside the frame channel beam. The red wire is spliced to the fuel pump wiring and the fuse was increased by 10 amperes. A fuel filter is used on the pump inlet and outlet. This protects the extremely close tolerance gear pump mechanism from abrasive particles and keeps out any pump particles from the pressure regulator and the microscopic hole of the injectors. The old pump was kept alive to aid in inlet delivery and reduce the possibility of vapor lock on the inlet side of the new fuel pump. Fuel hose was only used on the low pressure or inlet side. Solid steel fuel line withO-ring fitting to match the outlet filter was used on the outlet or high pressure side.
I now carry a spare fuel pump and with simple hand tools can replace it in about a half hour anywhere.
Because of the explosive nature of gasoline I must warn you not to do this unless you can make it a safe and professional installation. Jury rigging will fail and burn down your Motor Home in case of any fuel leakage.

Full.Monte · 09-24-2014, 07:49 AM

Quote:

Originally Posted by garyspang

FULL.Monte
I was not successful removing the fuel line special fittings so I had to cut the three plastic nipples on the pump with a hack saw then remove the hoses from the fitting stubs.

Hi ALDEV
I will get the information for you and crawl under the MH to take a picture for you showing the installation.
Hopefully by the end of the day.

Thanks, Gary...it's good to know what I'm up against. I bought the Harbor Freight gas pump pressure gauge yesterday so I can check the pressure of the in-tank fuel pump. That's next. However, I don't think the pump has failed. It's vapor-locking on hot days under load. I am considering splicing into the return line and re-routing it to the generator fuel line. The problem is I don't know where the generator fuel line goes into the tank on top...can't see it. If it goes to the third port on the fuel pump canister, I'll have to remove the tank. If it goes to a port anywhere else on the tank, I'll be able to finesse a repair through the generator line. The object is to dump the hot gasoline recirculated from the engine back into the tank rather than back into the fuel pump canister. Do you remember where the generator fuel intake was mated to the tank? Thanks again for your help.

garyspang · 09-24-2014, 10:47 AM

My generator fuel line came out of the top of the tank and went about 2/3 down inside the tank.
Check the pressure at the fuel rail. Leave the gauge attached and monitor it while driving. At the high delivery pressure over 60 psi, vapor lock is very unlikely. I do not understand how the return line can make a problem since it leaves the engine area. On my engine the regulator at the fuel rail relieves all overpressure to the return line so the rail pressure is purely a function of the spring reference pressure in the regulator dome and the attached feedback pipe from the intake manifold. As the manifold pressure is reduced from a closing throttle, it acts through the regulators diaphragm against the constant spring force to reduce the rail pressure. IE wide open throttle results in about 14 psi higher pressure than closed throttle (foot off the gas).
You might want to discuss your issue with an old fashion seasoned mechanic which I am not, I just read a lot..

Full.Monte · 09-24-2014, 11:06 AM

Hi Gary,
There are quite a few examples of vapor lock on the 8.1 on this forum. Here's the theory: gasoline is pumped out of the in-tank fuel pump to the engine. Some of this gasoline is used, the rest is returned to the tank, but not to the tank itself, but to the fuel pump canister. The engine heats the gasoline that is returned to the canister. On a hot day and under load (like towing or going up hill or both), the returned gasoline gets the contents of the fuel pump canister hotter and hotter until it vaporizes. By dumping the returned gasoline into the tank rather than the canister, it gets cooled and forces the pump to use cooler fuel from the tank than otherwise.
If you want to confirm the problem, use the search function on this forum and enter " vapor lock workhorse 8.1". So, if my generator fuel line is where yours is on the top of the tank, I might be able to use it as a substitute return line, thus saving me the trouble of removing the tank.

M&EM · 09-24-2014, 11:16 AM

Here are some fuel tank photos of bare chassis> 2004:

Full.Monte · 09-24-2014, 11:53 AM

Thanks! That's pretty cool! I enlarged the one showing the top of the fuel tank and even though it's pretty blurry, I think it shows a separate port on top of the tank for the generator intake. That seems to be confirmation that it's separate from the fuel tank canister.

M&EM · 09-24-2014, 12:15 PM

You can see more clearly at:http://www.irv2.com/attachments/phot.../IMG_46331.jpg

These photos are of a W24 I think. The fuel system on it uses the 3 port filter and uses a different pump assembly I think.

M&EM · 09-24-2014, 12:44 PM

I had my pump fail(90000) just after filling at Costco(not the cause), near Petaluma,Ca. this summer. They pumped 50 gallons into cleaned metal barrels thru an external pump and filter before dropping the tank. I didn't get to see the tank top so I wasn't sure if there was a separate fitting. Shop installed a WH pump labelled # 25178125 (made in Mex) and shipped over nite from Vegas. They refilled tank same way.

I had assumed generator line ran off one of 3 ports on pump flange. Now I'm not sure..