I have a D6D, and it is dead in the water-diagnosed as injection pump problem by the tech-fuel dribble out when when line disconnected from bonnet and cranked.  Finding a replacement is a problem for them-and little info available because the engine serial and machine serial arent accepted by any online site-not even Caterpillar. I assume its because of the age of the machine so I came here. Dozer Serial is 4X4146, Arrange Number 8P1544. the engine is a 3306 (cant tell if its a 3306B-same problem with no clear way to tell as the serial doesnt show up anywhere)-engine serial number is 3N80264, Arrange Number 7N1539.

I would like any help anyone can offer-the machine is a workhorse here on my ranch-and I need to get it going again. I have a full service manual and parts book I got on ebay, and I dont think replacing the entire governor and injection pump assembly would be needed-maybe. The assembly looks like it is part number 4N1836-but cant be sure as there are multiple figures depending on Engine serial apparently. Picture attached for help. Will be trying to remove filter today to see if there is a part number behind it.  Thanks for any help in advance-I need it!

Change the fuel filter and clean out the separator screen, blow out the fuel line from the tank and see what happens.
Bob

Well-pulled filter-and now have the part number from the pump-but after seeing what came from the filter-betting you are right about the fuel system before the pump before looking too hard at the pump. Look at what came out of the filter-the old old old filter. Where is the separator screen? Thanks for the help so far!

You really need a OMI for your D6D. The Operation and Maintenance Instructions contain much valuable info that will save you time and money
Good Luck,
Craig

The separator should be on the right side of the engine, a square glass bowl might as well change it. Be sure and drain the tank drain and blow back thru the fuel line from the tank.
I think that number is the pump body casting number.
Good luck
Bob

I do have the OMI-and like a fool, I have not been following any of the guidance contained in it-whicch I am going to start now.  Have new secondary filters in hand, and am going to start with fuel cap, new with its element, and then work from the bttom of a newly drained and rinsed tank through the lines, to the primary separator/screen/filter then to the secondary canister filter and blowing all lines clear to see if free and clean fuel flow can overcome the problem-only then looking harder at the injection pump itself.

Should I need to do so-tearing down and rebuilding the injection pump seems to need special tools? Anyone have experience with these pumps?

Thanks for the help to you all-will update you as I go.

Chris

injection pumps are best left to those with the proper knowledge and tooling to test and calibrate them. look for a shop thats been in business for a few decades more likely to have the old staff that have the experience and the gear to do these old systems.

when it come to parts ring your local dealer they can find many items tell them to look under classic parts if they cant find anything. it will cost they dont call em yellow money boxes for nothing.
also google is your freind if you can find the national stock number for a particular part you can find what else used it. works very well for bearings and seals. anything that was used by the US government department has a NSN and stock numbers were assigned to all the parts and it makes sense why order the same item 20 times just because each brand of equipment gives it a different part number. when you can order from the one supplier.

if you have access to a hot wash pressure cleaner use that and some caustic soda to thoroughly clean that fuel tank and get as much sludge, rust and crap out as you can this will prolong the life of the new filters.