What all does the transfer pump do? Does it just pump fuel up to the head or does it also have a check valve in it to keep fuel from bleeding past it?

Bob h please comment on this I promise to get alongLOL

Thanks Mike

I don't hold grudges Mike ... at least not for very long ; )


NO, the pump is not checked ... the fuel supply check valve is on the return side, and IT stands the fuel from there back through the pump to the tank.

Thanks Bob h

So the transfer pump takes the unused fuel and pumps it back to the tanks?

Does the check valve in the back of the head keep the fuel from coming off the fuel rail?

My truck starts hard after it has sat for a day with 1/4 tanks of fuel. Anything above a 1/4 and it would start fine but now it seems to be doing even with 3/4 tanks.

I changed the check valve in the back of the head about 3 years ago but the IH dealer gave me the wrong one. I can't remember for sure but I think I needed MPT going into the head and he gave me FPT so I took the body of the check valve apart and used the guts from the new one and put it in my old body. So I really didn't remove the check valve from the list of things that could be wrong, because maybe there is a small crack in the body?

I have asked a couple local Mechanics and they thought maybe one of the pick-up tubes in one of the tanks were cracked. They are welded in and the tanks would have to be cut into and rewelded to even see if this is the problem.

When it acts up it does not have any fuel to make the motor even spit or spudder. I roll the truck over 8/10 seconds two times and the third time it grabs fuel and runs fine. After this the truck starts so fast you can't get your finger off the button quick enough.

Thansk Mike

could definitely be an air leak. Check fuel filter bosses as well.

Thanks Allan Bob h do your fingers have laringitis? LOL

Thanks Mike

Take your cup of coke from your combo meal you just picked up at McD's (sorry) , push the straw to the bottom and put your thumb over the top of the straw to seal it. Now, pull the straw out of the coke until just before the bottom end of the straw comes out of the coke; you now have a stand of coke in the straw... if there is a leak anywhere over the length of that straw, the coke will all leak out.

As Allan mentioned ; air leak. And also yes the fuel pick-up tube in the tank could be cracked; this would explain the leak-back being fuel level dependant, and getting worse over time... cracks under stress/vibration eventually become breaks.

Thanks Bob h good way to describe my problem but I like Mountain Dew.

Now if I pulled the straw to within 1/2" of being out of the Dew and there was a pin hole in the straw in that 1/2" would there be enough pressure from above the Dew line to let all the Dew out of the straw or would it stay up to the top of the straw?

Bob I looked for a long time on line last night for a site that showed the S60 fuel system. Just a drawing that showed the routing of the fuel. Is there somewhere on the net I can find this?

Thanks Mike

If the pin hole is fully submersed... the fuel stands.


...haven't you had a 'dew' since you read this ?

Ya I have had several but I don't use a straw.