4020 JD- Advice needed!

M Nut · Jul 21, 2009

Hey guys,
I'm needing some advice to point me in the right direction. I had the injection pump rebuilt on the 4020 because it had a pretty bad external leak this spring. Got it back, and the tractor missed on one cylinder and smoked pretty nasty. I then pulled all injectors and had them tested, and they all tested weak. I bought all new injectors from Deere and installed them this evening. Got the tractor started it it still missed on the cylinder closest to the radiator, smoked pretty heavy, and then started dumping oil out of the muffler, not gushing but like a steady stream of oil. I shut it off and pulled the valve cover, but the valves and valve springs all appear to be working correctly when I turn it over. Where do I go from here?

I have a compression tester but it only goes up to 300lbs. Is that enough for a diesel motor to check the compression on that cylinder?

Thanks for any pointers. Spent $1300 so far and things have only gotten worse, kinda hoping to turn this around and start making progress!

Allan in NE · Jul 21, 2009

Kinda sounds like a scalded piston. I'd go with the compression tester you have.

If a piston is bad, you'll read close to nothing on that cylinder.

Allan

4010 puller · Jul 21, 2009

Do a compression check and double check timing.

mEl · Jul 21, 2009

Was it running ok before pump removal except for the leak? I would double check the timing if it was. No hurt checking the compression but good compression will possibly destroy a 300 lb gage, I suspect good compression would be nearer 400 lbs or a bit more. mEl

Dave from MN · Jul 21, 2009

Sorry to hear your having woes with that 4020, hope the 886 is treating you good. I'll have to send you some pics of the calves and that meatwagon shorthorn I bought.

M Nut · Jul 21, 2009

It had developed a miss on one cylinder so I quit using it and that's what really made me finally bit the bullet and get the pump rebuilt. I guess it sure can't hurt to double check the timing, but I had everything lined up when I pulled the pump and I double checked it when I reinstalled it. But, it is a cheap thing to try. Thanks for the advice.

M Nut · Jul 21, 2009

Yeah, this old 4020 has been our main workhorse for the last 10 years and we have done nothing to it besides change oil and add fuel. I suppose it was just a matter of time until I would have to put some money into it.
886 is treating me great. It has taken over for the 4020 on the discbine for cutting and it is the only tractor we have baled with this summer. Use it almost daily with no problems. Put on a used air conditioning compressor this spring for $20, charged the system, and even the air is working really well. (course haven't really needed it either with the temps we've been having)

dieseldoc · Jul 21, 2009

Did you check the rocker arms on that cyl.?They do break sometimes.Check compression first and if you dont find a problem pull rocker cover off and take a look. Also the camshaft could be wore out and not letting valves open all the way. good luck.

teddy52food · Jul 21, 2009

Leave the fuel shut off and spin it over with the starter. If one is weak you should be able to hear it.

4020 JD- Advice needed!

M Nut

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Allan in NE

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4010 puller

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mEl

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Dave from MN

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M Nut

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M Nut

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dieseldoc

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teddy52food

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