Unsticking a diesel pump

If this is the injector pump, are you quite sure it's "gummed up with old diesel"? The clearances on those are incredibly fussy, and one of several classic ways to catastrophically kill them is hosing off a hot engine (cooling the cylinder(s), shrinking it(them) onto the piston(s), destroying the pump).

Rebuilding these pumps is generally acknowleged (at least among the old-tractor do-practically-everything-yourself folks I've gotten a lot of old tractor advice from) not to be in the realm of normally equipped shops - there are shops that specialize in them, and they have very fussy tooling indeed, as I understand it - I own an old diesel tractor and I've not had to have the pump rebuilt thus far.

You might try an ultrasonic cleaner with the ATF soak step (carb cleaner in an ultrasonic cleaner sounds far too hazardous to me).

try penetrating oil soak for a few days then make an adaptor that takes a grease gun fitting and fits into the outlet of the pump. A few shots of grease should easy it out ( btw there might be a check valve on the outlet). Make sure that the cylinder is as full of grease as you can get it, air trapped inside hampers this method and can create a missile. Pat

The clearances are very tight on diesel injection pumps. Even the corrosion from touching them with your bare hands is enough to seize the piston and cylinder. The injection pump piston and cylinder should be dismantled in a container of diesel using suitable gloves to prevent contamination

It is normal practice (in the UK at least), for any fuel injection pump work to be sent to a specialist due to the specialist equipment required to set them up.

Fuel Injection pumps are quite a simple design, it's just the tolerances and set-up that require specialist equipment.

Remove the top cover on the pump. Drain the diesel. Spray PB Blaster on all the pumping elements inside the pump. Remove the injector lines and spray PB Blaster in all the high pressure outlets . Let it sit overnight. Rotate the pump over and see which ones are still sticking. Buy the tool from cat and remove the offending pump element. Disassemble and free up the element. Reinstall making sure the sleeve engages the rack paw. Torque to 70 ft.lbs. If carefully done settings will remain intact. Do not force anything.

And make sure the timing pin isn't in the pump.

Thanks for the replies. I'll do the carb cleaner soak and ATF soak method. More info about the pump: it froze up from sitting for two years without operating. It seems the sleeves somehow managed to disengage from the control rack pawls on one side before we attempted to start it, so cranking the engine did some bad things. One, all eight pumps were stuck and got forced up their bores. Two, those four sleeves that slipped off the rack got hammered into the rack and forcefully pushed down their pistons. Three, that rack got turned out of adjustment. Four, after all that one dumbass thought it would help to loosen a few screw on the racks. So it's not a happy pump. It would be best to send it out to get work done, and that's the first option if they can pull it off within the school's piddly budget, but failing that we can borrow all the needed calibration tools and do it on-site. One of the instructors has a fair amount of experience with fuel pumps from long ago, and I'm known for being extremely anal-retentive so the two of us will probably work on it, with me doing the work and him supervising and answering questions.

To those that helped, I reward you with pictures!

Interesting stuff, B.B. I admire your persistence. Thanks.

Garrett Fulton

that sure looks like a simple engine to work on.

replying to Pat Ford, Parker McMillan wrote: So how does the grease get to the stuck pumping element if there is a check valve??

TRANNY FLUID IN THE TOP IS THE BEST WAY NO QUESTION ABOUT IT