John deere 310c broken injection pump shaft

[Mr580backhoe!]

Hello ive come across a possible very good deal on a john deere 310c tlb. I don’t have to many details on the machine yet as im going to look it over on Saturday. What i do know at the moment is the gentleman who owns it was using it parked it came back to it a few days later it wouldn’t start discovered that the injection pump shaft had broken. He replaced the shaft got it going again parked it came back a few days later same problem all over again. This time around he put a new injection pump in it got it going used it a bit came back some time later on went to use it to find the shaft had broken again. My question is what would make the shaft keep breaking? Is there something that could be wore out and is binding up and the shaft just happens to be the weak point? Ill be able to provide more information saturday after i look at like the hours and serial number and such. Any thoughts or input would be appreciated thank you

 

[mekanik]

Is it a Stanadyne pump? If so it has a groove machined in the
shaft where it will break instead of damaging the gear train.
I strongly suspect it had water go through and seize the pump
or possibly gasoline.

 

[stinky64]

I could swear that when doing research before rebuilding the roosa pump on my 580C I read something in one of the forums about if your power steering pump goes dry and $hits the bed/seizes, the grooved shaft on the injection pump will snap like mekanik said...I inquired about this issue here when another feller had some other issue that may have been related, but nobody had ever heard of such an issue....I may be imagining things, I consume a lot of beer,but check the power steering pump and inquire about steering issues with the owner..

 

[Delmer]

if the injectors are plugged, where's the fuel going to go? there isn't a relief valve in there...

 

[Mr580backhoe!]

Thank you to everyone who has replied. I will be taking all the suggestions into conversation when i go Saturday to look the machine over and I will report back with my findings and decision on weather to buy it or not

 

[Tinkerer]

Perhaps this may give some insight as to what can go wrong and break shafts.
https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=jd&th=256853

 

[hosspuller]

Interesting bit about tying the throttle back before installing pump. Could be reason a new pump failed if installed incorrectly.

When I removed my pump for 310C I set the timing and tied the throttle back as instructed. Rebuilt pump was supplied with the linkage tied back and timed. Didn't know why, just did as instructed. Now know the weights can jam the pump, breaking the drive shaft.

 

[Mr580backhoe!]

Thats very interesting im going to inquire on that Saturday when i go to look at it. It seems that even the littlest bit of dirt or water can reek havoc with thease injection pumps as well.

 

[thepumpguysc]

Plugged injectors, or just 1 injector.
Mechanical misalignment. (Gears or the way the pump is held on)
Water/dirt in the fuel..
If it kept happening w a different pump, I’d look at the causes above.