Hey everyone. I have a 1994 F150 4x4, 302, almost 257,000 miles, and she has the original fuel pumps. I think the rear pump is starting to get weak. Makes a slow pulsating sound every now and then. A couple questions. First, is it true that if one of the pumps (it has dual tanks) starts going bad, that it will then start filling the other tank? I heard that somewhere. Also, how hard is it to replace the pumps? Sounds pretty straight forward. I also need to replace the rear tank completely. Had a small leak, patched it a couple years ago, has held since, but if Im dropping the tank anyway, would be a good time to put a new tank in there (this is the rear tank).
Also, anyone know what the fuel pressure at the fuel rail should be?

 

starters, if you got the money, id just replace the tank, nothing would me off more to get the tank back in with the shiny new pump to have it start leaking a week later.

iv never heard about them start cross filling if one pump goes bad, usually they cross fill because of a bad valve i believe in the frame rail pump.
(someone correct me if im wrong)

your fuel pressure should be 35-40 PSI

 

They can start filling the other tank if a valve goes bad but usually the pump
Just quits. And I have a hard time believing they are original pumps. Not to often they make it past 150k. They're pretty easy to do...if the tank is empty. Personally I like the bed removal method. Just 6 bolts hold it down, a few buddies, and it's off. But if you have to drop them, just run it till they're as empty as you feel is safe to get you home. I don't know if your year has the fuel lines on the pumps that need the disconnect tool. Someone else may be able to tell you for sure. Nothin worse than gettin the tank halfway down and not being able to get the lines off.

 

Yes it will cross feed...and the best way to access the tanks is to remove the bed...6 bolts /filler neck and light harness...you will have great access to do whatever you want...I would do both pumps while you are there...it's hard to believe the with 257K miles on your truck that thoses are the orignal pumps...good luck

 

Yours will only have the pumps in the tanks.

Yes they are bad to crossfill when the check valve in the pump assembly goes bad.

Yes you will need the line tool to release the connector on the pumps, also you may have a inline check valve at the pumps so take it off also and make sure it's clean and working before putting it back on. Ford had a recall to install these due to the pump checks going bad.

I have always dropped the tank but on my next one may pull the bed to try it that way. Also you can get a tank/pump assembly that comes together to save having to buy both seperate if you need both.

As how long the pumps will last I swapped one out on my front tank at 230k miles it was a Motorcraft pump but the PO may have had it put in.

 

yep they are original...I bought the truck new back in 1994 and do almost all repairs myself...never been replaced. Original untouched engine, tranny, and clutch too.

 

Where can you buy the combo from? I was looking at a tank from lmctruck.com and a Delphi pump.

 

Lol...seems nobody believes they are original but I bought the truck new in 1994 and I know the are original.

 

You can pick them up at most part stores AutoZone, O'Reillys I was looking at one for my truck the part # is F1G1FA.

 

sound like my dad... he had a ranger with the original clutch for 280thou kms. mechanic said there was still meat left when he switched them out.

just goes to show how long these trucks are built to last with proper maintenance and a good owner.

your probably one of those guys that doesn't let his tank get too low very often eh