hAVE 1990 f 150 i REPLACED REAR FUEL PUMP NOW IT PUMPS THE GAS INTO THE FRONT TANK, dOES ANYONE KNOW THIS PROBLEM AND THE REPLACEMENT KIT FOR IT

 

The check valve/shuttle valve in the front tank is malfunctioning. Replace the front tank fuel delivery module.

 

Thanks


Is the valve inside the tank?, as luck would have it my front tank is leaking and needs to be replaced

 

I believe so. I'm trying to think of a work-around, but I can't come up with one. The fuel could either be entering the tank on the pressure side or on the return side. Ford fitted external check valves for a recall, but the check valve wouldn't help on the return side (would definitely help on the pressure line of the front tank). Maybe try calling the local dealer and see if they can still source those check valves. Or if you use the front tank or plan on using it, just replace the tank and delivery module and be done with it. One other possibility is to run it on the front tank (if possible) to burn up the gas that gets transferred.

 

When I took to old pump and sending unit to Advanced Auto the sales person removed what looked to me like an external check valve saying I did not need it. Could this be a problem? or does the front pump control the flow problem

 

Your front pump return check valve is shot .... that is probably where it is filling from, my front tank had the external valve on the supply side and was overfilling from the rear. If you can find a check valve for the return line size similar to the one on the supply side that will keep gas from going into the tank .... you could effectivly fix the problem until you are ready to replace the entire tank and pump assy.

I do believe you need the check valve on the rear tank that the person said you don't need. I have not checked my rear tank yet, but I have one on the front, I can not start the truck on the front tank, so either the new pump is not building enough pressure, the check valve is not allowing the fuel past it easily enough, or the rear tank doesn't have a check valve and the pressure is not building up from the front tank, about to hit the shop and check all this out.

 

Thanks for the reply, I'm getting ready to change out the front tank. I ordered it today. I can check out the valve at that point


Thanks again

Bill

 

Pay attention to what EPNCSU2006 said, he is correct and yes the valve is in the tank and also inside the fuel delivery module.
The fuel delivery module:
http://i54.photobucket.com/albums/g9...yAssembly2.gif

 

Subford .... so if there is a high pressure check valve inside the pump, would I need to keep the external one that Ford put on there for one of the crossflow fixed in years past?

I got my truck in the hobby shop today, we checked the fuel pressure, I get 49PSI from the rear, goes up to 54PSI or so when I give it some gas, will drop to 47PSI when I let off before returning to 49PSI .... for the rear pump.

The new front pump gives about 45PSI max, and will drop to between 30 and 35PSI at idle.

I put the truck on the lift and checked that there is an external check valve on the rear, and there is, and proceeded to remove the check valve on the front tank to try test the pressure from the front tank without it. When I removed the 1 month old plastic clip it broke in half .... the barbed side stayed in there, and having 2 or 3 at home and none with me, I decided not to take it off to make my trip home possible less expensive ... no tow bill. I checked under the truck when I got home to make sure there was no leak, and didn't find one, but found one of the intact old clips from when I changed the pump right under the truck.

I am going to try removing it again (and have extra plastic clips) and checking PSI and that I have no crossflow, do you think the check valve may be restricting the flow too much? Blowing through it from both sides when I had the pump out, I couldn't blow in the direction it is supposed to block, but it was very hard to blow through the way fuel is supposed to go.

 

thank you Gentlemen really apreciate your help

 

Subford

Do you need the external check on the rear tank

 

johny b & SilverSport

As far as I know the external check valve and the recall that put them on was just for the 1993 Fords, they had a bad run with the check valve in the fuel delivery module that year. I do not know of any recalls on any other Ford truck for the cross flow problem. These Fords were bad from the factory in 1993 and that is why the recall. Of course there have been other cross flow problems and some have tried putting the check valve in to correct it but I do not know if any have worked or not.
The shuttle valve can also cause the cross flow problem and is more than likely the cause on trucks other than the 1993. Older trucks (89 and older) with the selector valve had a an "O" ring sticking problem that filled the front while running on the back and like the shuttle valve on newer trucks (90 and newer) an external check would not help in either case.

The external check valve, if one has been put on, should flow free in one direction and block in the other.

If you replaced the fuel delivery module in the tank then no you do not need an external check valve on that tank.

Note that I said fuel delivery module and not fuel pump.

 

SilverSport

What size fuel tank is your front tank, I purchased a 19 gal but it looks to long

 

Subford .... there were about 1.1 Million trucks on that recall and 1.5 Million on the pump issue. I found it here http://www.internetautoguide.com/auto-recalls/67-int/1990/ford/f-150/base/index.html

I called the dealer in town, they are the only place to get the check valves from. I got the part #, but need to be sure it is the right thing before I post it. It is supposed to come with 2 of them and the FPR for about $65. Of course they do not stock it and it doesn't show up in parts schematics or made by anyone in the aftermarket, even motorcraft.com doesn't have it. I will make some calls and try to find a dealer with that part #. I don't want to take it off, then have a problem starting because of it not keeping fuel pressure primed in the line .... the other reason they used it. I can't believe with them being used in so many vehicles they don't have them more readily available for when one clogs up like mine has.

Johnny B .... Mine is a 16 Gallon, but have seen them listed as a 17 Gallon also. The Standard cab shortbed used the 16 Gallon ... the 19 is too long, but I believe it will fit the Extended Cab SB and the Standard Cab LB.

 

I stand corrected, Ford never had a recall on the hi pressure check valve in the tank.

The recall was for the Fuel Pressure Regulator in the 1993 model year and it would cause the hi pressure check valve in the FDM to go bad and cause a cross flow problem.
Here is a link to it:
https://www.ford-trucks.com/recalls/...y-1993/t-54351

They did however have a fix for the cross flow by putting in a check valve in the supply line from the tank if the truck was still under warranty and the warranty on this was extended for 12 years from the year of the truck.

The link you posted above is not from Ford and is not a Ford recall, it is a NHTSA SAFETY IMPROVEMENT CAMPAIGN and as you may note there is not any Ford number in the posting.