kind of an old thread, but thought I would reply for others following in our wake. My knowledge is limited to this particular pump. Seal kit on eBay is $25 and has all the parts
you need, with a pile of leftovers.
The leak is indeed between the main body and the hydraulic head
(distribution cylinder). There is a small O-ring. It can be replaced without disturbing the timing or governor mechanism or the high precision parts
. Keep all the parts rust free by submersion in clean diesel
Remove the cable bracket and cables
. I found it easiest to completely remove the fuel lines to the injectors. The banjo bolts that attach the fuel lines to the head
do not need to be removed, but they can be if you think they are leaking. Then disconnect the inflow fuel line to the end plate and remove the end plate. Inside there are 2 vanes for the fuel transfer pump and an eccentric silver liner. If you pull the rubber seal it makes removing the vanes and eccentric piece easier. The cross slotted pice needs to come off. It removes counterclockwise. I cut a piece of 1/8" steel
about the width and it came off easy. Don't bugger up the edges with a screwdriver, etc. Stick a clean towel in the hole.
Remove the governor mechanism off the top. Removing this piece is intimidating as the bolts are safety
wired and have a lead crimp seal. Fear not, the wire is only to keep them from loosening, not a critical adjustment. If they loosen, the governor rises up, not only causing a leak, but also potentially preventing the stop lever from working. It is held in place with 2 bolts. There are different head types, mine had a 12 point 1/4" head, so you need either a 12 point socket or box wrench. Most common this size are unfortunately 6 point. Lift
it strait up, it has a finely machined surface. Keep crap out of the empty hole once removed.
Once the governor is off, it makes access to the main body bleeder bolt (aft side) and fuel pressure cutoff switch easy. They have to come out completely.
Next is the advance device off the bottom. One little 1/2" cap nut closet to the block first, then the big 3/4". The big one has a little detent ball that will potentially fall out, so be prepared to catch it. There is an extra in the seal kit if it gets away.
Now you are ready to remove the hydraulic head. Twist will loosen it up. Look inside the governor hole to see it start to move. I had to whack the banjo bolts with a plastic mallet to start it moving. As it comes off, try to keep the rotor in the pump body by pushing on the shaft that the fuel pump cross piece attaches to. If it comes out, replace it promptly, the shaft is keyed so it only fits one way. I had one banjo bolt that I could not remove, so I had to completely remove the hydraulic head. I suspect if all the banjos are removed, that the head does not need to come off completely to slide a new O ring in place.
Once replaced, reassemble in reverse order, twisting to get the hydraulic head in. A little diesel lubes the Oring to make it easier. The rotation of the head into the body is critical in getting all the pieces to fit. Use the bleeder bolt and switch bolt as guides, they should go in easy by hand. Use all the new gaskets and sealing washers in the kit.
There is a new safety
wire and crimp for the governor so it looks "official".