# JD400 Slow Hydraulics



## Jamie Parkinson (Mar 7, 2020)

Hi All,
I hope everyone had a lovely Christmas. My 1970/71 JD400 has very poor back hoe and front bucket hydraulic operations and even the steering is 'how's your mum' when operating the bucket. I believe the issue started to occur after I replaced the filters. I don't have any manuals (Which I'll go to the local JD dealer once open and get them) and have read similar issues (See post below) however, my knowledge on the hydraulic operating system is not as good as I'd like. Can anyone offer some simple initial checks/guidance to get me on the right track to fix this . Thank you.

JD 410 Backhoe slow hydraulics | Tractor Forum


----------



## Tx Jim (Jul 28, 2020)

Have you checked/cleaned hyd oil suction screen(item 30)? I also suggest to check to be sure filter relief valve(item 18-20) isn't stuck open. I also suggest to acquire a 5000 psi gauge & check hyd oil stand-by pressure which should be 2250-2350 psi.. Does your tractor have a hyd reverser? If so does it operate correctly?


----------



## Jamie Parkinson (Mar 7, 2020)

Tx Jim said:


> Have you checked/cleaned hyd oil suction screen(item 30)? I also suggest to check to be sure filter relief valve(item 18-20) isn't stuck open. I also suggest to acquire a 5000 psi gauge & check hyd oil stand-by pressure which should be 2250-2350 psi.. Does your tractor have a hyd reverser? If so does it operate correctly?


Hi Jim,
Nice to hear from you again, I'll get to work on these items. You may need to explain Hyd Reverser, I'm not sure what this is. Thanks Jim and talk soon. 
Jamie


----------



## Tx Jim (Jul 28, 2020)

Hyd reverser has a control handle on LH side of dash similar to turn signal handle on auto/pickup


----------



## Jamie Parkinson (Mar 7, 2020)

Tx Jim said:


> Hyd reverser has a control handle on LH side of dash similar to turn signal handle on auto/pickup


Thanks Jim, I thought this is what you were referring to. Yes the tractor has the Hydr Reverser, its operating OK. Thanks mate.


----------



## Tx Jim (Jul 28, 2020)

Hyd reverser operating correctly indicates trans pump is functioning & should be providing oil to frt hyd pump.


----------

