John Deere JD400 service manual

[Wacka100]

I have a John Deere JD400 loader backhoe with hydraulic issues could any one help me out with a copy of a workshop manual to help to try:shocked:and start sorting out the problem.

 

[Tx Jim]

:welcome: to TBN
I can't help with TM but 1st thing you need to do to tractor if you haven't already done so is change hyd filters & check/clean sump screen(parts key 15). There will be a fitting with a hose holding screen in trans case not shown in parts photo. What is tractor not doing?

 

[Wacka100]

Hi jim tractor will only lift the bucket when machine is moving forward but will not allow backhoe to operate

 

[Jet A]

I don't know if this will help or not.
Make sure clutch is released when using the hydraulics. There is a feed pump in the tranny that provides fluid to the fwd engine driven pump. Also my manual states to have the reverser in FWD if using the backhoe.
Have you tried cleaning your filters and screens and perhaps replacing your hydraulic fluid?

Alex

 

[Tx Jim]

Hi jim tractor will only lift the bucket when machine is moving forward but will not allow backhoe to operate

Did check trans screen? You could also check trans filter relief valve that shown in photo to be sure it's not stuck open? Get gauge and check stand-by pressure which should be 2250 psi

 

[buickanddeere]

Why not call 1-800-522-7448 for the real JD manuals ? The parts book is free online at the JD web site.
Countless front pumps have been changed by guessers when the actual problem was a lack of oil being pumped up to it's inlet port.
A leaking closed Center hydraulic valve, a leaking/stuck relief relief valve or if somebody has added an open Center hydraulic valve will cause problems.

 

[Tx Jim]

Make sure clutch is released when using the hydraulics. T
Alex

Alex
I thought that on units with a reverser that the trans pump was driven from pressure plate not traction clutch shaft so whether traction clutch is engaged or not is mute. Granted my knowledge of ind tractors is limited as I was employed by an "AG only JD dealership".
Jim

 

[Jet A]

Jim,
I'm new to the JD400. I got mine a month ago and do have the parts, service and operator manuals.

The operator manual states,
"The transmission oil pump supplies oil for the main hydraulic pump. Therefore, avoid prolonged disengagement of the engine or PTO clutch which controls Oil pump operation. Disengaging the clutch for long periods reduces supply of pressure oil for hydraulic functions."

It is not specific to the installation of the reverser.

again, I just got mine and I'm sure you've had more experience than me, it's just something I found in the manual.

Alex

 

[skot0123]

New JD400 owner trying to chase down hydraulic problems and springing new leaks as I fix old problems. Is there a trick to getting the screen out? I have pulled the 1 1/4 bolt/plug and see the end of the screen but can't get it out. I've tried snap ring pliers, screwdrivers, a dowel but can't get it to budge. I don't see a plug on the other side that I could remove and push but maybe I'm wrong.

 

[Tx Jim]

Welcome to TBN
It sounds as if the sump screen is crumpled. One has to get tough when the screen is crumpled or badly coated with sludge.