feets

I've got a nasty leak on the pump of my 92 D250. With the truck running it drips every couple seconds. It's difficult to run down the culprit but I think it's the control valve if I understand the sticky post correctly. Everything's wet with fuel around the same piece the wrench is on in this pic.




What are the chances it's something else like a shaft seal under the linkage that is leaking?

Right now, this truck is all I have to get around. My daily driver is in the body shop.

BearKiller

The control-valve is a relatively easy fix, once you either make a special wrench or are lucky enough that it is oriented such that a crow's-foot will loosen it.

I cut the open-end off a 10-MM wrench (or was it 12) and welded it onto a standard nut, 3/8-nut---9/16-head if memory serves.


Were I you, I would follow the plan in the "sticky" and reseal the control-valve.

Then, if the leak is still there, next suspect would be the throttle-shaft O-ring; not quite so easy as the control-valve, but still an easy fix none-the-less.

I have had good success by matching the O-rings with those found in a large Harbor Freight metric nitrile O-ring assortment and they have been leak-free for years.

In fact, those Harbor Freight O-ring sets contain many O-rings that fit various places in the VE pump.

DodgeFreak

or just pull the top off replace throttle seal and install the 366 spring and while the tops off replace the control valve seals.

feets

Thanks guys. I'll dig into it as soon as I can.
Will there be any need for priming the fuel system again or should it fire up and rattle itself to a smooth (for a diesel) idle again?

BearKiller

If those two points are all that you mess with, then it should fire right up and run as always.

Just to be certain, I would pump the primer-lever about thirty licks prior to cranking.

jimbo486

You'll be just fine if you fire it up after resealing the control valve. If there just so happens to be a small amount of air inside the pump, it'll purge out. As long as the fuel hasn't been drained from the high pressure lines or the hydraulic head, there's no need to prime the pump.