Darn fuel pump! Please help.
 

1986 F250 XL, 460 gas engine

Well I almost had an engine fire the other day. The diaphragm in the fuel pump sprung a leak and was squirting a pretty thick stream of gas onto the engine...but I caught it in time. I'm trying to fix this myself to save some money. I didn't have too much trouble getting the old fuel pump off, but I can't get the new one on. The problem is the portion of the pump that is between the two bolt holes is wider than on the original pump and consequently a socket and extension has to be held at an angle. See pic below. The angle doesn't look that bad in the pic, but it is. If the red line were to represent an extension attached to a socket, you can see that the socket and/or extension would hit the widest part of the pump body. On the pump I removed, that same area is much narrower, like the top of the pump.

http://i437.photobucket.com/albums/qq93/mcclintick_2008/Fuelpump.jpg

I've spent nearly 2 whole days on this, removed various parts (power steering pump, radiator hose, a bracket support on the alternator, fuel line to the carburetor that was in the way) just to make more room and tried different tools (socket attached to straight extension, swivel socket, open end/box wrench, ratcheting open end wrench) and just cannot get the bolts in far enough. As the pump base gets closer to the engine block the angle and surrounding parts won't allow me to connect a wrench. If the pump were shaped the same as the one I removed, it would just be a straight shot with a socket and 6" extension.

I've looked at various websites (auto zone, o'reilly, pepboys, etc.) and all the pumps seem to have the same basic shape. I tried looking for the original Ford part, but the sites I've tried don't come up with any result for my truck. Not sure if the one I removed was a Ford part or not.

Not sure what to do here. It doesn't look to me like the old pump could be rebuilt, or I might try that. Do you guys have any suggestions?

It shod be the same size as the old one.

This is what autozone shows for a 86 250 460
http://i13.photobucket.com/albums/a2...ps00a56d8b.jpg

Yeah, that one from auto zone look very much like the one I bought. It won't work. Here's a pic of the one I removed. The thing sticking up above the bolt holes is much narrower...

http://i437.photobucket.com/albums/qq93/mcclintick_2008/fuelpumporig.jpg

Maybe I'll go to auto zone tomorrow and take a look just to make sure.

As you start to tighten the pump up to the timing case the arm is riding against the cam eccentric.
I just force the pump up against the case with my other hand.
Maybe turning the engine over will put you on the low side of the cam and make it easier?
Using a 1/4" drive socket and extension would gain clearance.

This pic was showing the difference in PS boss between C2 and Saginaw, but you can see the fuel pump pretty clearly down there.

http://farm9.staticflickr.com/8261/8...8dc9da7c7e.jpg


Have you considered just using a different style bolt?
Maybe an Allen with a washer?
That, with a ball end 3/8" drive would eliminate any clearance or angle problems you could possibly have.
Spending a couple of bucks at the hardware store seems well worth it compared to the frustration.

Where was the fuel squirting out?
Usually when the diaphragm fails it fills the crankcase with fuel.
I've never seen one leak from the crimp.

I went to auto zone to look at another brand of fuel pump - airtex instead of precision - but it was shaped similarly and I would have the same problem. Jim, thanks for suggesting the allen head bolts and wrench with ball end. I might end up having to try that. If I could find a 9/16" universal socket that is only wide at the very end where it fits over the bolt instead of all of the way up - if you know what I mean - and connect it to a 1/4" extension, that may work. Don't know if they even make one. Anyway, I'll look around for a tool solution instead of a pump solution.

As far as the leak, there is a "port" on the side of the old pump, maybe 3/8" in diameter. At first look I thought maybe a bolt or some tubing was supposed to be connected there, but there are no threads, it just looks like a port. Anyway, gas was squirting out this opening. I am just assuming the diaphragm is broken and I'm not sure what the "port" would be for exactly.

I don't smell any gas at the end of the dipstick. Do you think I should change out the oil and filter anyways?

Alan

Alan,
Welcome to the forum. :-wink

If the oil level is correct, not watery on the dipstick, and doesn't smell like gasoline then I would not worry about it.

Try rotating the cam.
Try holding the pump against the timing case with one hand so it's easier to get the wrench on it.
I remember it as a juggling act, but not this much trouble.

...Snap-on TMU 181.
Or, MAC MU 186. :eek:

Amazon seems to have a set of shallow, universal, fractional, 1/4" drive sockets for ~$20

I know that Amazon have same day and box drop delivery in much of the Bay Area.

I finally got it! I was about to remove one of the bolts and take it down to Lowes to find a couple of Allen head bolts the same size. But i decided to just jump on top of the engine, get mad and Bogart it. Got a few scratches and a sore back but i got them in using a regular socket and 6" extension at an angle. Thanks for all the suggestions Jim.