4640 power shift loss of hyd to remote then sterring

   / 4640 power shift loss of hyd to remote then sterring #1  

grdavis2011

New member
Joined
Mar 16, 2011
Messages
1
Tractor
4640
Loss fliud to the remotes and then the sterring started going out. Where do I check pressures to see if I have a bad pump or a valve problem. and where the valve would be. I have heard there is a valve that priortizes where the fluid should go so you will have brakes and sterring.. please help 4640 jd power shift thanks. pictures or instructions will greatly be appreciated
 
   / 4640 power shift loss of hyd to remote then sterring #2  
I'd be checking the brakes! I'd pull the filter and see what is inside! What you haev is often the first tell tale that the brakes are shot and they are clogging up the hydrauilic system.
 
   / 4640 power shift loss of hyd to remote then sterring #3  
Do you have a shop manual?

Do you have pressure guages one for low like up to 600 psi and one up to 3000 psi?
 
   / 4640 power shift loss of hyd to remote then sterring #5  
i had a 4430 that had the same type of issue. what the problem ended out to be was a snap ring in the final drive (axel) broke and the gear rubbed on the housing which filled the sump up with filings which plugged up the screen on the suction pump. the hydraulics quit, steering, brakes, and even the powershift trans. it was compleetly dead in the water except for the engine running. shut off to check out stuff, and started up again and ran for couple minnutes and stoped again. pulled filter and was full of filings. brought to shop. hope yours isn't that bad.
JD's have two pumps one in rear end (sump) which pumps oil to power shift and feeds front pump for high pressure. i don't remember off hand if it also feeds brakes and steering or if that comes from the front/main pump. something to check into.
 
   / 4640 power shift loss of hyd to remote then sterring #6  
Could be as simple as the screen filter in the sump gets old, mushy and collapses or a seal is blown and just consumes too much oil, like the pto or differential lock.

Get the pressure gauges and some hydraulic fittings.

Think simple.
 
 
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