Replacing Injection Pump?

Discussion in '1982-Present GM Diesel' started by 79Beast, Dec 6, 2005.

  1. 79Beast

    79Beast 1/2 ton status

    Dec 9, 2001
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    Last Sunday I brought home an '84 C20 with a 6.2 that the guy "wanted out of his yard". It's a pretty clean truck with brand new tires and a 10K mile TH400. He was driving it every day until one morning it wouldn't crank. He was told the injection pump was bad and I guess the cost to fix it wasn't worth it to him. I had another 6.2 with a good pump, but cracked cylinder head that I was gonna swap. My question is, do I have to remove the water pump to release the I.P. from its drive gear? If the drive shaft slid right out of the pump, is it junk or can I put it back in? Also, where is the best place to get a reman pump? I'm not looking for blazing performance, just a good reliable truck to haul stuff around in its 8 foot bed and maybe tow the occasional trailer.
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Jul 23, 2000
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    E-town baby!
    If you remove the oil filler tube you'll see the bolts holding the pump shaft to the gear. You can get one bolt at a time (there are three) and you'll have to rotate the engine for each bolt. If memory serves there is a dowel and the 3 bolts are not quite concentric so it can only go back together the right way.

    Once those three bolts are out then you can undo the injector lines and remove the three external bolts holding the pump on.

    There is a plunger and spring on the end of the shaft, don't send that part in when you get the pump built...I made that mistake and ended up having to source another one locally which was a pain.

    Sounds more like a glow plug relay or controller went bad. IP's can cause a few different things but it's usually not overnight and not all at once. My truck started smoking more and more over a few weeks until it I thought my neighbors might call the fire department the next time I started it...:crazy:

    I'd do some basic checks before ripping the IP off and getting it built.

    I had my IP and all 8 injectors rebuilt by Tim at
    Cost me $347 US at the time and that included shipping. That was nearly three years ago now.


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