Update on noisy 4010 hydraulic pump

Well we bought a new drive for the pump. The one with the rubber bushings. This didn't help it much. We put a gauge in the rear outlet and the pressure is around 1600 but the needle fluctuates back and forth about 200 psi. Then we took off what we thought was the priority valve that is mounted up under the cowl on the right side. I believe this actually just a connector for all the lines. There is absolutely nothing inside except drilled passages. We then put the gauge on the line coming directly from the pump. We are getting a fluctuating needle here also. It goes from about 2500 to 2000 real fast and as soon the engine shuts off it goes to zero. So I am leaning toward the pump being the problem. It seems to have a stuck piston or the valves are leaking badly or something. I know you can buy a rebuild kit from deere but it looks like only O-rings. Anybody had any luck rebuilding these or not. Could it just be the stroke control valve?

By the way this pump does have a destroking screw on the bottom of the pump and when I screw the screw in it does destroke the pump and it quits making noise all together and also the hydraulics quits working as it should.

Time to rebuild the pump . It has valve issues or pistons worn or both . Should pump 2250psi and a steady needle . The priority valve only distributes oil AFTER THE STEERING AND BRAKES get first 1700 psi .

Keep us posted on this issue. I have one very
similar issue as yours. How does your hydraulics
work raising up a baler or disc mower or something
like that?

There should be a valve and spring inside the priority valve.
Didn't it push against the fitting you removed?
You should replace the pump instead of wasting time on it.

Jim, I just rebuilt a pump for a 3020. It was not the first I took apart but it was the first I completed and it worked great. I did consider a pump from Tractor Parts A.S.A.P. (Also known as All States Ag Parts) at $850. I had used one of their pumps on a 4020 with good success. They were also good at making sure you got the right pump for your tractor.

So, if you have the tools to disassemble the pump and knowledge to assess which parts need replacement, go for it. If you are unfamiliar with these pumps you may want to consider the one for $850. On the last one I did I had to replace the main shaft. After all was said and done I am not sure I saved much.

Good Luck. Paul

We decided to try taking out the stroke control valve and the seat on it was all beat up. We were going to buy a new one but jdparts lists a couple different ones for a 4010 and the one is no longer available. I don't know for sure but this tractor is a real early model and I figure this is the one that is no longer available. I am a machinist so I reground the stroke control valve and also the seat for it sort of like you would regrind valves in an engine. I also lapped it with real fine lapping compound. We put it back together and the noise is better but still there. The pressure fluctuates much less but still about 200 lbs. This is my sons tractor and he bought it mostly to pull at the tractor pulls. We also have a 7' john deere flail mower that he will probably put on it to mow our pasture field. He already has about $5000.00 in the tractor and right now he really doesn't want to spend any more money on it. He is going to pull it on may 27th so he is just going to run it as is. The hydraulics work fine its just noisy. Maybe later in the summer we will pull the pump off and rebuild it.

This pump is kind of odd. The pressure adjustment is on the top and the destroking screw is on the bottom. The stroke control valve comes out the top. We havnt hooked the remotes to any kind of implement yet. We did put a gauge in the one tonight and we are getting about 2200 psi.

There was nothing inside the priority valve. Actually I believe this one is just such an early model, it doesn't have a priority valve.

I was told once by our block man that deere had an update program to install the priority valve on all those early tractors. Your tractor may have slipped by.

How long have you owned tractor??

There are no serial number breaks so I'm guessing someone before you removed the pressure control valve internal parts to get 3 pt/scv to operate.

Our 1961 4010 JD hydraulics acted the same as described, brakes and steering were normal but the rear outlet and 3 pt were very slow, even though the outlet pressure checked OK. I replaced the hydraulic pump, but the problem only slightly improved, then sold the tractor and never got to the root of the problem. The tractor acted like the pump was starving for oil, using the 3 pt or rear outlet made the pump clatter, as though it were running empty. Always thought there must be a proven systematic method to find the original cause and it still bugs me that I did not correct the basic problem.

(quoted from post at 13:20:16 05/18/16)
How long have you owned tractor??

There are no serial number breaks so I'm guessing someone before you removed the pressure control valve internal parts to get 3 pt/scv to operate.

Click to expand...

I'll get a picture when I get home of the part that is where the priority valve goes but ours doesn't look like the one in the illistration

We have only owned the tractor for about 6 weeks.

here is a picture of the valve on this tractor.

Here is a picture of the tractor but we are putting 20.8 38 tires on it