Finally did the fuel pump

[blackf3504dr]

Well after much procrastination I finally got around to changing the fuel pump (91' F53 chassis). Thanks to subford and all his advice it was easier then I anticipated. I cut an access through the floor instead of dropping the tank and the near 50 gallons of fuel in it. The only hitch is the heating duct runs the length of the coach right down the center and required cutting a section of it out also. My measuring showed the pumps location to be just a few inches out side the platform for the bed. I pulled back the carpet, marked my opening and cut away. After cutting the heating duct I was right above the pump with plenty of room to work. It really was a piece of cake and it fired right up and runs great. Oh, after reconstructing a section of heating duct, securing a couple of cross members to support the cut out section of floor and reinstalling the section of floor I stretched the carpet back and theres no sign anything has been done.

[CARSMills]

Sounds like something I would do... the challenge of dropping any RV fuel tank is not a pleasant task. I have an 89 Class E350 and I'll remember this short cut if I have this fuel pump failure.

[Jagtech]

I also cut an access hole in the floor of my rig. I can now change that fuel pump in about 30 minutes, in a campground if necessary. And no need to siphon and store 30 or 40 gallons of gas!

[blackf3504dr]

Well, if not for the fact there was 50 gal. of fuel in the tank and who ever ran the hydraulic line to the rear right leveling jack under the tank I would have dropped the tank. I'm just glad it's done ! Now I'm working on the ladder, replacing two of the star nuts/bolts that secure it to the body.

[cneira]

My 97 dutch star has a welded brace between the leveling jacks running under the 75 gallon fuel tank. Thanks for the idea of cutting the floor. Before I complete my diagnostics to confirm I have a bad fuel pump I would like to test the wires at the fuel pump. Does anyone know the electrical readings I should have at the fuel pump. I have a four wire harness- red/black, black/red, black and yellow. Thank you.

[subford]

You should have about 12 VDC for one second when you turn on the key with the Pink wire with a black stripe. The Black wire is ground going to the frame.
The yellow wire with a white stripe is from the gauge and could have any voltage on it.
The other wire with black on it is also a ground wire for the gauge.



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[blackf3504dr]

Quote:

Originally Posted by subford You should have about 12 VDC for one second when you turn on the key with the Pink wire with a black stripe. The Black wire is ground going to the frame. The yellow wire with a white stripe is from the gauge and could have any voltage on it. The other wire with black on it is also a ground wire for the gauge. /

How did I know subford would know that ? cneira, once I decided to cut the access hole the job was easy.

[cruzn57]

FI 460, no running issues,
fuel line to Gen sucks air, ( gen won't stay running) pressurize tank, and fuel leaks from top of tank, same issues with dropping tank,(full of fuel)
I have a rear bedroom, and am considering cutting a hole in the floor.
is there room between floor and tank? ( so I don't cut tank, or anything else!)
I'll replace all hoses,
unit has 45k mi, should I do fuel pump too?
ford fuel pump, or aftermarket?

thanks!

[subford]

I think you can get to the hose on the top front of the tank without dropping the tank on a Class "C" 1989 E350.
Others in this thread were talking about the F53 Class "A" fuel tank.
You should only have 32-35 Gal tank.
If you have two tanks it is only about a 19 Gal Tank.
I think you have about 3 or 4 inches between the bottom of the home and the fuel tank so if you want to cut it I guess you could but I would not.

[cruzn57]

was told it was 35-37 gal.
front of tank is right next to rear axle,
one or two fuel pumps? in looking for new fuel pumps, it shows lo press and high press ON SOME MODELS.
pics only show two lines on fuel pump, where does gen fuel line connect?

Thanks

[blackf3504dr]

Quote:

Originally Posted by cruzn57 FI 460, no running issues, fuel line to Gen sucks air, ( gen won't stay running) pressurize tank, and fuel leaks from top of tank, same issues with dropping tank,(full of fuel) I have a rear bedroom, and am considering cutting a hole in the floor. is there room between floor and tank? ( so I don't cut tank, or anything else!) I'll replace all hoses, unit has 45k mi, should I do fuel pump too? ford fuel pump, or aftermarket? thanks!

On our 92' HR class A there is about 10" between the top of the tank and the floor of the coach, room enough to check things out but not enough to pull the pump out. As long as you're in there I would replace the pump, I know it's a lot of money but I don't want to have to do it on the side of the road. I could raise the back of the coach with the leveling jacks and by crawling over the rear axle I took measurements and generally checked things out before I cut the opening. subford was very helpful and has a bunch of knowledge (thanks again subford).

[subford]

Quote:

Originally Posted by cruzn57 was told it was 35-37 gal. front of tank is right next to rear axle, one or two fuel pumps? in looking for new fuel pumps, it shows lo press and high press ON SOME MODELS. pics only show two lines on fuel pump, where does gen fuel line connect? Thanks

Below is your fuel system but there is one more tube coming out of the tank at the top of the fuel hanger with a fuel hose on it that goes to the generator. The tube inside the tank is an open tube and just goes 3/4 of the way to the bottom of the tank. This is so you will not use up all of your fuel and be out of fuel for the 460 engine, There will not be any problems wit this tube inside the fuel tank:


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[cruzn57]

but BIG thanks!
that makes sense, I wondered why the gen hose sucked air ,but not main fuel supply hose?
do you suggest replacing Both fuel pumps, or just one,( which one?)
again many thanks for the information.
Hope you get a winning lotto ticket for your reward for all the help here!

[subford]

Quote:

Originally Posted by cruzn57 but BIG thanks! that makes sense, I wondered why the gen hose sucked air ,but not main fuel supply hose? do you suggest replacing Both fuel pumps, or just one,( which one?) again many thanks for the information. Hope you get a winning lotto ticket for your reward for all the help here!

The fuel pumps have nothing to do with the fuel going to the generator.
The generator has its own electric fuel pump mounted on the generator.
You should be able to get to the fuel hose to the generator from the tank at the tank without dropping the tank and replace the hose all the way to the generator.

There are three tubes on top, One is the pressure tube to the engine, Two is the return from the engine and the third one goes to the generator.


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