JD 400 Backhoe filling transmission by draining the implements.

   / JD 400 Backhoe filling transmission by draining the implements. #1  

veewee

New member
Joined
May 28, 2014
Messages
10
Location
Victoria Australia
Tractor
JD 400 backhoe
This unit is causing me much grief! I fill the header tank above the pump, and everything works for a short spell, but then it pumps this oil into the transmission, thus overfilling it. I have replaced the hydraulic filter and removed the valve and spring that seems to isolate the oil flow through the large diameter hose at the bottom of the filter body, and that seems to be the only connection to the transmission reservoir. This valve consists of a ball-end and spring and almost sealed off the oil flow as I was replacing the filter, as there was only a slow dribble. The other plug in the filter body is just that, without any valve inside. The JD Parts drawing shows a valve setup and I ordered these parts but there is noway there is enough room to fit them, so I assume that they refer to a different setup to my unit. ( $76 wasted!) Can someone out there please give me your suggestions.
 
   / JD 400 Backhoe filling transmission by draining the implements. #2  
Leaking charge pump in transmission?
 
   / JD 400 Backhoe filling transmission by draining the implements. #3  
Are you referring to the small tank located above the high pressure pump, near the radiator?

You are not supposed to fill that with oil......it is filled by the transmission pump, with oil not required by the high pressure pump. It's a closed center system, so the main pump will only use the oil that it requires to maintain pressure.

Do you have an issue where the hydraulics work ok sometimes, but get shaky and don't move other times? If so, you have a lack of adequate flow to the high pressure pump, or a leak in one of the high pressure circuits directly into the transmission - on my old JD300, I had this problem with the 3 point hitch valve.
 

Tractor & Equipment Auctions

FORD COBRA REPLICA RACING CAR (A51222)
FORD COBRA REPLICA...
2015 KUBOTA 1140CRX RTV (A51406)
2015 KUBOTA...
2020 CHEVROLET Z71 TEXAS EDITION TRUCK (A51406)
2020 CHEVROLET Z71...
2005 Construction Trailer Specialists BDT-40 T/A 40ft Trailer (A49461)
2005 Construction...
2012 FORD F-650 SUPER DUTY BOX TRUCK (A51243)
2012 FORD F-650...
2017 Peterbilt 567 Tri-Axle Dump Truck (A49461)
2017 Peterbilt 567...
 
Top