644D Brakes

[steve931]

I am having problems with brake pressure on a J.Deere 644D.I have 2800 lb,s of pressure at the unloader block but I am losing it somewhere between the accumalator and foot valve.,any idea will be helpful. Thank,s Steve931:usa

[Countryboy]

Welcome to HEF steve931! :drinkup

[steve931]

Welcome to HEF steve931! :drinkup

Thank,s:usa

[surfer-joe]

If it isn't leaking externally, which would be highly visable, then it may be leaking internally at one of the brake applicators and then be flowing into the axle housing, or into one of the planetary housings and then back into the axle housing.

It may be bypassing at the foot valve right back over to the return side and back to reservoir.

I do not have any specific ideas as have never had to work on this model, but it's not hard to check the possibilities I listed as an easy 1st or 2nd step in trouble-shooting.

Good Luck!

[steve931]

Thank you very much for your reply.The foot valve seems to be working properly,I am not building enough pressure to the foot valve,I will put your suggestion in my notes,I think I might have a priority valve issue. I will let you know, again thank you for your time.:usa

[steve931]

After beating my head on the wall for a few weeks I finally found a bad relief valve.The valve was stuck open therefore letting the fluid run in circles.Thank,s for any replies.Steve931:usa