No fuel from injection pump

toolz

Well-known Member
My 4020 engine replacement is done, but I can't get the injection pump to work. I have bled everything, and have fuel to the pump. The engine is from an early 7700 combine, CBC633-26AL. The fuel shut-off has a faint click when I turn on the key. Is there a way to make sure it's opening? Any suggestions before I take it to the rebuilder?

First pic is the CBC pump, second is the DBGVC on the blown engine. Would like to change it over, but the mount is different.
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You can remove the fuel cutoff plunger but if engine cranks you'll either have to block off the air supply or ride the brakes in high gear to kill it.
 
You can make the old pump work by having a bushing made and a clamp style hold down, I have done this several times and worked out good.
 
Tim- That sounds like a good idea. I happen to have a lathe and a chunk of aluminum that needs a home. Is the pump drive and height the same?
 
The fuel shut-off solenoid on the C pump has two flat screwdriver slots on it. Two flat-ended screwdrivers will work to take it out. It just unscrews. Take it out and inside there is a little plunger and spring. If you take the plunger and spring out and then put the big piece back in - it is "run" position, all the time. You'll have to stall the tractor though - to shut it off.

I hope you realize that that C pump is obsolete and nobody in the USA has new parts to fix it. A few shops have used parts laying around and can patch those pumps up - but that's about it.

To put the better DB pump on the engine - you just need some adapters.
 
Thanks LJD. I did pull the solenoid out this afternoon- it"s working fine, and the pump is clean and full of fuel- just doesn"t put anything to the lines. Tim suggested making a bushing to mount the DB pump, and that will be the solution, since I know that pump is good. It will also look factory and hook up to the linkage.

Does someone make an adapter kit? It doesn"t look like it will take me long to do it, but if I can buy them, it will save some time.
 
I turn the bushing to a nice slip fit, "BUT" you need to leave a small thin lip on the outer top side so it don't try to slip down, seal it up as you go together, but first make your "C" clamp hold down and drill the holes insuring good fit first,,the shaft is the right length and the small lip will hold the pump up just a bit but not enough to hurt anything,,I got several of them running around here like this, working just fine...sure it's not just exactly right, but it still gets the feed ground...
 
Yes Jim that's the clamp,,I made a few using one for a pattern..the pin is not necessary..the clamp will hold it in place..
 
The later db pumps will fit the hole or use a bushing. I cut the bottom off of an old db and used it for a templaet and drilled and tapped holes . I never made a bushing so I dont know what was used or how it stayed in place without falling down .
 
We make them with a thin lip at the top to keep them from sliding down...works out good...
 
I thought I might just use a small pin through the bushing slightly into the pump to hold the bushing up, or drill through the block behind the tach drive for a roll pin into the bushing. Also thought I could make two hold-down clamps, similar to a distributor hold-down, for each side of the pump flange.
 
What are you going to do with that CBC pump if you use the other one? i would be interested in the pump and lines if you would sell them?

Thanks,
Zach
 

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