JD 400 Backhoe pulsating weak hydraulics

[olde man]

those old manuals are like gold pending on the tractor i've seen them bring $50 and up for just one thin little manual at antique equipment shows

 

[JimmyBOD]

Thanks for all the tips. I can see that I need to do more to get ahead of this. I bought the tractor from a man who owned many machines. I doubt if he kept up wth the maintanence.

 

[Gale Hawkins]

those old manuals are like gold pending on the tractor i've seen them bring $50 and up for just one thin little manual at antique equipment shows

I paid through the nose for my old JD oem shop manuals but I could not keep it running without them. I find the parts manuals being very helpful because they show the exploded views.

 

[veewee]

Most interesting following this thread. My problem with my JD400 Backhoe is that when I last worked the front bucket the hydraulics emptied the oil out of the filler cap on top of the differential until it drained the rams and I had difficulty getting the bucket high enough to get back to my house. I have fitted a new filter but, the plugs on the filter body don't contain any of the valves as shown on the JD website One just has a rod in the centre and the other has a strong spring with a ball shaped end that doesn't fully cut off the oil from the transmission, as it keeps dribbling into the filter housing after being refitted. I may have created a problem for myself by overfilling the hydraulics, as it was not until I was changing the filter that I noticed a Knurled cap low on the RH side of the manual gearbox and discovered that it was a dipstick and lot of oil flowed out. Any thoughts out there?

 

[Tx Jim]

:welcome: to TBN
Sounds as if you have ""way too much oil"" in trans. Correct method to check the oil level is with engine running and knurled cap with dipstick setting on the threads of extension. I think the 2 things that you need to procure is a model 400 operators & JD tech manual. Hyd's will never operate correctly with the correct valves absent. I also recommend checking/cleaning trans oil sump screen(parts key 15). Access to screen is on RH side close to hyd filter by removing a fitting that has a hose on it. Oil will need to be drained to check screen

 

[veewee]

Thanks for your advice Tx Jim. My setup is different to the one in your diagram, as it is a casting with 3 hoses attached and a cylindrical body parallel to the side of the transmission, but does have a 1 inch plug which I assume contains the screen. As we are in drought with temps 40C here in Oz, and my machine is out in the open, I will continue working on it at a later date and post my results. I don't know whether the overfill caused the front bucket to drain it's fluid, but I'll soon find out.

 

[Tx Jim]

Thanks for your advice Tx Jim. My setup is different to the one in your diagram,

You're very welcome. Sorry you're experiencing a drought. I forgot that sump screen retainer fitting is different on ind vs ag tractor but I think screen is in same location in trans case.