3020 hyd issue

I bought a '68 3020 syncro that has a hydraulic whine/rattle coming from up front. The steering works fine, brakes are good, but the lift arms seem to need alot of lever input to raise and then they are jerky and slow to raise (I have not tried the SCV yet). Ive drained and replaced the hyd oil, changed the filter, and cleaned the screen with no change. I bought a 3000psi gauge and plugged it into the scv, at an idle it makes 2200psi. I performed the trans pump test into a bucket and it produced 3 gal in 30seconds. I have no doubt that the check valve is bad and I intend to fix it, but would the check valve cause the loud noise up front? The lift arms are slow and chatter even after the tractor is warmed up and running for quite some time.
 
Be sure your foot is not on the clutch which will prevent the charge pump from doing its job. There is also a screen
in the inlet of the hydraulic pump up front that can be cleaned, but I don't know if the pump has to come out to get to
it.
 
No I'm not on the clutch at all. I was going to pull the screen from inside the main hydraulic pump but I had my reservations that it is the culprit. It would require me to pull off the front end which I'm not apposed to doing, I just wanted some more opinions before I do.
 

When attempting to raise 3 pt where is L/D lever set? I'd suggest to put this lever in "D". Filter in hyd pump is an unlikely problem. Have you checked stand-by pressure? It should be 2250 but 2350 is better.
 
Odd thing is when I first start the tractor (because of the faulty check valve) the tractor is quiet until oil gets to the main pump. As soon as oil reaches the main pump it starts knocking & banging again. I also noticed this while I was testing the trans pump, while the oil was diverted into the bucket the tractor was quiet. The thumping sound is definitely coming from the main pump. Any ideas on what is causing the noise?
 
Its definitely internal. I can feel the steel line jumping near the 90* bend (heading toward the priority valve) while the tractor is running. A friend thought it may be a hyd pump bearing, but the pump does not leak fluid.
 
It is "possible" that a couple of the pump pistons are stuck, which would allow pressure but low flow,,and a noisy pump,,I'm thinking if you have good charge oil the pump should come down out, if you would like to ship it to me I could run an 'autopsy' on it to see if it's got any good left in it,, most pump at this age can be re-sealed but have a lot of wear in them, a new after market pump is the best option for about $900
 
I pulled the front end off the tractor today and will begin the pump removal soon. I noticed the # r42663 on the housing and after a brief search I can not match that # with a main hydraulic pump. I found plenty other #s on ebay referencing jd 3020's. Did they really put that many different pumps in these tractors?
 
(quoted from post at 14:58:14 09/10/16) ya, I forgot to mention that I replaced all the rubber bushings.

There is the rubber vibration absorber which is different from the coupler that splines onto the front pump. As previously stated worn splines sound awful.
 

where is this vibration dampener located?
I took the pump apart today and aside from a slight amount of gulling on the pistons it looks good as far as a visual inspection. I was expecting to find carnage. now where do I search?
 
I replaced the main hyd pump with a rebuilt unit. I fired up the tractor and all rattling & knocking is gone. It appears to have very good rock shaft function and good pressure at the svc (2250) without surging. As soon as I perform Geralds external check valve replacement, ill get it out and see how she works in the real world.
 
follow up: I pulled the main pump and upon disassembly it was badly worn. I replaced it w a reman pump and the issues are gone. thanks everyone for the help.
 

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