George Heiler

I just recently bought a 1990 F250, 7.5l XLT Lariat. It is an awesome truck.
My leading problem at this point is my fuel system (I already had a valve job done on the heads).
My front tank is full, and feeds the engine gas. Meanwhile, the fuel gauge is incorrectly reading empty.
My back tank is full, but does not feed the engine. Annoyingly, the gauge WORKS, and reads full when I switch to the back tank (therefore the switch works as well).

I have not had problems with a tank overflowing, and I have read a lot about that being a common symptom with this model.

So do I need a new fuel pump/sender for the back and some sort of sensor for the front??

For anyone who is interested, my other leading issue is my cooling system. My mechanic pumped it, put in a new thermostat and some hoses, etc, and the radiator is fairly new. It ran great for the last couple of days, but now all of a sudden it is overheating. When I feel the upper hose I can tell the thermostat is not letting fluid through...I am not sure why.

memoniz

I have the bed to my truck off right now, changing both fuel pumps. I drove for years with my fuel gauge working on and off on my front tank. That pump went out early in the year. My rear tank worked fine until one day it stopped. I was at a light with a weeks worth of groceries. I about gave up trying to start it when I switched it back to the front and it started?! Drove it for a couple of days and truck died completely. I had it towed home. Thinking that maybe something else is the problem, I bought a new tank selector switch. Now I have a new switch in a non running truck.

Most everyone here will tell you might as well get a new pump. The front one might be working now, but it will go. The rear probably is gone. Run some tests first though. New sending unit will fix the gauge, I think.

On your cooling question, when does it overheat? What I mean is mine overheated once upon a time as I sat still, and would cool as I drove. That problem was the fan clutch. There is the possibility the thermostat is in backwards.

George Heiler

Thanks for the quick response.
How hard was it to get your bed off? And do you have easy access to the pump and sending unit? Also, do you know if I can replace those things without taking the bed off--in other words how difficult is dropping the tank(s)?

It wasn't overheating for a few days after getting it back from the mechanic, but randomly it got too hot driving around, and sitting still, both. The thermostat was opening just a couple of days ago, and now it doesn't seem to open.

Thanks

midnightduddie96

I dropped the tank on mine but thats just cause i had to replace the whole thing. If you take the bed off then both pumps are right on top of the tank, easy as pie to reach. if you take off the bed, id grind those bed bolts away, and buy new ones. then you just have to disconnect fuel filler necks, tail light connectors and probably some other things im forgetting

George Heiler

I think I will replace the fuel selector valve, and if that doesn't work I will go forward with taking the bed off. The fuel pumps are not cheap though!
Also, it will be a fun game for me finding the various nuts holding the bed on, and I lost my Haynes manual.

Thanks.

memoniz

Removing the bed is one of those things you think "boy, this is going to suck". But it really doesn't. Living in Raleigh, rust isn't a big issue. I have 6 bolts and only one gave me a problem, and a pair of vice grips solved that. Two electrical connections, disconnected the filler tubes at the body, 4 guys and lift. Going to put new shocks on while I'm at it. Also my bumper is rolled from a previous rear end crash that I will be taking to a body mechanic friend to straighten out.

I waited on ordering the pumps so I could get a good look at them. I ordered from RockAuto. $268 with the express shipping. Not to bad. Should have them Thursday. And that also includes a filter. One reason I went this route is because one tank is full, the other half. And the thought of laying on my back dropping fuel on me just isn't appealing.

You may want to flush your cooling system again to see if something is clogging it up before you spend anymore money.

memoniz

To answer your other question, the pumps are sitting right on top. I'll be able to take them out standing over it. Be aware that you don't want to drive the lock ring with something that will cause a spark. Can't seem to find a brass punch, so I will probably use a piece of hardwood.