John Deer 300 Loader/Backhoe Hydraulic Pump

[Frozen001]

I am looking to possibly purchase one of these, owner states the pump needs to be replaced. Couple of questions:

1) What is the best way to tell if it need to actually be replaced when I go look at it. Are there certain signs that it is the pump and not something else
2) Can the pump be rebuilt?
3) What would a new pump cost?

 

[Tx Jim]

Buying a JD tractor with closed center hyd's that has problems is asking for HEADACHE's. To correctly diagnose closed center hyd's requires gauges & flow meter. Hyd pump can be rebuilt as long as housing is not cracked & piston bores aren't worn out. There are several different pump possibilities so I just picked one in the middle range. This price is from JD but there are other aftermarket pumps available. AR97872 PUMP,HYD,ASSM 40CM3 J PORTS MOD EA1 ADD 2,205.51 USD

 

[medic0648]

What is the issue/s it is having? Does it have a fel?

 

[Frozen001]

I am not going to know until I go and look at it. It has a loader and backhoe. This is the e-mail I got when I questioned what was wrong with the hydraulics:

- I am not a mechanic, but I am told by our grounds crew that the hydraulic pump needs to be replaced -- and there may be some finessing of valves in the hydraulic system as well. Other than that, I am told it works fine -- and we're just tired of putting money into and having our grounds guys work on it, when they can/should be mowing grass!

I am going to look at it Friday, so I want to be prepared to know what to look for and what not to look for. Here are photos:

 

[Tx Jim]

Many closed center hyd pumps have been replaced without proper diagnostics being performed which results in a tractor with a "new pump" that still won't function properly hydraulically

 

[Frozen001]

Thanks for you input. I will have to keep it in mind when I look at it.

 

[medic0648]

Easy way to make sure it's not the valves failing is to remove the return line and see if there is fluid flowing with no valves actuated. This means a valve is failing and needs to be replaced.

 

[Tx Jim]

Easy way to make sure it's not the valves failing is to remove the return line and see if there is fluid flowing with no valves actuated. This means a valve is failing and needs to be replaced.

I agree with you but other functions such as steering and reverser can contribute to poor hyd performance.