Found alternative to AMBAC's $38 viton spacer for MEP injector pump !!

[donaldl]

Gentlemen;I refused to pay Ambac $38 for their Viton spacer that seals/spaces the delivery valve in the MEP diesel injector pump.
I found a supplier for Viton fuel hose that matched the OD on the supply valve holder.That hose has a 10mm ID.that fits snugly over the delivery valve holder,measured at .409 inches with calipers.I then had to match the outside diameter of the fitted hose/spacer to the bore of the injector pump it fits into.That dimension is approximately .456 inches.The Viton hose is .544 inches so I had to remove .088 inches.
I made an arbor and fitted the hose on it and mounted it into my lathe.Finding the Viton hose too pliable for machining I taped it to my arbor then I placed it into the freezer.It seemed to help.
I machined it down to .048 inches in thickness.I installed my new spacer/seal and found that I was not getting injection even though I was getting fuel to the injectors.So I backed off the loading on both injector nozzle springs.My experimentation showed fuel injection at 1200 PSI using my POP tester.Put it all together and it RUNS Whoopie !! Worked the engine splitting wood for an hour with no problems.
Now I know the springs for the nozzles should be set at 1950 PSI. Because I am not producing those pressures I think my seal MUST be the wrong dimensions.So if I had the AMBAC Viton seal dimensions I could duplicate another seal.In fact I have enough hose to duplicate 80 seals !! So does anybody out there have that OD. Viton seal dimension.? Hope this info helps others as Ambac should not be charging us or the government $38 for a .80 cent seal. Sic Semper Tyrannus

 

[Triple Jim]

Rubber is usually ground, not cut with a lathe tool. You'll probably do better with a Dremel tool and grindstone either hand held or mounted to the tool post.

 

[donaldl]

Triple Jim;I used a sharp file and several freezer cycles.My arbor was a transfer punch that the hose fit onto snugly.I have read that some SS members do not have this spacer on the MEP injector pumps.Does that mean the manufacturer sealed this cavity with closely machined tolerances?

 

[donaldl]

Gentlemen;I posted earlier with a link to Ebay on another source for this Viton spacer but I see it is not here.If you search this phrase:repair/rebuild kit DE56: ....you will find a listing for Viton spacers. According to the seller the listed 12 "lower" spacers have a dimension of 10mm; that will fit snugly over the delivery valve holder in the MEP injection pump.The OD on the spacers would then either have to be custom made or with some luck be a perfect fit.