I just noticed that the fuel pump to number 1 cylnder is leaking on my 5T. I am assuming it is the o-ring inside that is bad. The last one I changed they gave me the o-ring at the Cat dealer. Man, what a pain to change. I am wondering if it would be easier to change out the whole pump, replacing it with one off of the 7J parts tractor. I have noticed that the injectors are different on the J. Are the pumps the same?

Thanks In Advance,
Ken

It might just be the "O" ring seal under the pump fuel inlet tube and it,s a 2A3307.

SJ: Thanks for the advice. I think the leak is internal on the pump though. Because it is coming out over the top of the pump. Maybe the line running to the injector not sealing, but I really doubt it. I have a new dilema, I have started it about 3 times, since I noticed the leak, it only leaks when turning it over with the pony. Once the diesel lights off the leaks gone:eek: . I even idled the diesel down as low as I could get, right on the verge of it stalling. Still no leak with the diesel running. Doesen't matter if the diesel is idling or running full throttle. There is no leak when the diesel is running, I am baffoled:confused: . I thought a leak was a leak. Anybody ever heard of this happening? The Cat laid in slumbers for about 30 years. Any help would be appreciated.

Thanks,
Ken

Hi Ken,
Your early 7J with clamp down style injectors uses the same pumps as your 5T.
We just had a post not to long ago on the same leakage problem.....came down to either a gasket leak under the star nut or a split ferrule (fairly common) on the fuel injection line........never did hear back on the conclusion. If it requires getting into the pump I'd just change one out from your parts machine.

Can't really explain why your seeing the intermittent leak but a poor ferrule seal might leak under reduced pressure while cranking and seal under operating conditions.