If your problem is not that the fuel pump drain is clogged or crimped and the fuel is filling the chamber inside the side cover on the pump housing, then my guess is you need to remove the governor housing off the back of the fuel pump housing to get access to the nut that holds the plug with the seal on it.

There's not a good view of the plug and seal in the parts book. With the governor housing removed, this part is visible below and inboard (toward the engine) of the rack bar where it comes out of the back of the injection pump housing. Parts book shows the seal, plug, lock and nut on a stud which is screwed into the injection pump housing.

Do you have a Serviceman's reference book for the D318 engine?

It basically says to remove the back cover from the governor housing, disconnect the link to the rack bar and then unbolt the governor housing and remove it.

If you take the side cover off the injection pump housing, you can move the rack bar back and forth while looking through the governor housing and see where to disconnect the linkage in there.

"ccjersey" wrote:

Do you have a Serviceman's reference book for the D318 engine?

Unfortunately I do not. Not trying to be a smart ***, but how does a oil drain plug have anything to do my the leak around the governor control? This is all greek to me.

BTW: Thanks for the help. I really need to get this fixed.

I posted a reply before & it didn,t go through & I lost it but anyway there are 2 external drain plugs, one under the inj. housing & one under the gov. housing & both are for oil that lubricates them but the oil is only put in the inj. housing to fill it as it runs back to the gov. but the low cavity in the gov. won,t drain if just drain the inj.housing. There is the other plug & "O" ring seal in the back of the inj. housing that seals off the fuel supply passage that feeds the inj. pumps themselves & is behind the gov. housing when it,s removed. There is a 1/4" external drain tube that drains off any fuel that slips by worn inj. pump plungers. In the D4 6U parts book it shows that fuel passage with a plug up to 6U11578 & then on up the housing is not bored clear through so a cover & seal is not needed any more. I don,t know if a high SN D6 U series is the same but I,m sure it must be but don,t have a parts book to see if & when it changed as the D6 housing & gov. is pretty much the same as a D4 except it has 6 cylinders.

Hi SJ,
It's the same deal with D6 "U" models. The fuel passage plug went away at sr. # 9U26422. Otherwise its the same seal as used at the filter housing, 8B4967. I believe you can see the plug area through the governor once the back cover is removed. Haven't checked my spare parts to see if you could access it for replacement without removing the governor.

Here is a view of the plug and nut etc that holds it in.

This is looking at the rear of the stripped down injection pump housing with the pumps, side cover, governor, governor drive gear and the rack removed.

The fuel pump drain line I was referring to is an open drain tube that drains the compartment below the pumps so any fuel leakage goes on the ground instead of diluting the lube oil in the injection pump housing sump. It should be routed from the front of the pump housing, down along the left front side of the block, just behind the front cover and held by a clip fastened to one of the bolts holding the front cover on the engine. A problem with the drain line would be an easy fix compared to replacing the seal in the rear of the fuel supply gallery.