JOHN DEERE 1020 PRESSURE CONTROL VALVE

Hi guys, I'm new to the forum so bear with me!

I have a later model (1970) john deere 1020. I bought it at an auction so i don't have any maintenance history.

My problem is the 3pth being slow to rise with or without an implement on it. The tractor runs great, drives and shifts very well. The line coming from the front hydraulic pump is vibrating in and out of the pressure control valve, the valve itself sounds like its chattering when the 3pth does lift a bit then the 3pth stops and so does the chatter. I have put new hydraulic oil in, the old oil wasnt milky or full of air bubbles.

My 1020 has manual steering and no hydraulic remotes. Also has a rear and mid mount pto. The brakes both work great. One side note is the previous owner had a mid mount sickle mower on it, it has since been removed. I did notice they plumbed the hydraulic line coming out of the backside of the pressure control valve into the bottom cover of the filter screen.

Hopefully someone has some ideas on whats wrong, I haven't checked pressures yet. I'm thinking maybe the pressure control valve is at fault?

thanks in advance for any advice!!!
 

Welcome to YT
Whomever routed oil line from rear of pressure control valve to filter or screen didn't understand closed center hyd's very well. Remove the line in question & install plugs in both orifices. Did you check trans oil sump screen to be sure it's clean?

On subject of pressure control valve I'm thinking only tractors after serial >45,200('67 model) that came with power steering were equipped with a pressure control valve. Manual steering models had a 90° fitting or tee instead of pressure control valve.
 
I would go slow on the diagnosis. First I would remove filter/screen and drain out all the fluid from case. The hydraulic fluid is used for transmission and hydraulics. I would be sure to check for any residue/metal material etc. I would say this would be about $100 in cost. I would try to get all the fluid from the front reservoir. Then I would test out thoroughly for any mechanical problems. You can then decide if you need to go forward. Why do brain surgery when you may need an aspirin.
 

Im pretty new at all this, and I also just aquired a 1020...Does it make any difference what position the 3pt rockshaft selector lever is in as to the speed of lift? Seems that it made a difference. I was taking the 1020 out for a little shakedown cruise after changing out the load shaft seals, draining hydraulic fluid and changing filter, seemed like it raised slower when the selector was in the 'L' position.
 
I worked on the tractor today I removed the line and capped
the pressure control valve end and the screen filter where
someone had added the hydraulic line, drained fluid, checked
the big screen which was clean as a whip and changed the
transmission filter Hooked it all back up and now my 3 point is
staying in the full up position even with the hand control down.
The only way I can the 3 point down is to turn the tractor off. I
took the rear hydraulic fill cap off and it sounds like it is hissing
inside. The tractor sounds like it?s labouring whenever I move
the 3 point control lever even though the 3 point stays up Any
ideas?
 

Try the three point hitch lever 3/4 of the way up and check if it still labours.
The extra line at the ported filter cover is for return oil from a loader, backhoe, hydraulic motor , wood splitter etc .
 

My guess is cam follower(key 6) is broken or not located in correct place in linkage or spring(key 7) is disconnected. These parts are located under rockshaft housing. With aid of flashlight look in hyd filler hole to view cam follower. Have you tried moving hyd L/D control lever under seat to different setting?

mvphoto18936.png
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top