2020 Hydraulic Q's

[46stude]

Long time listener, first time caller......

I've got a '71 or so 2020 that lost PS, 3 pt lift, & PTO all at once. Did a ton of interweb searching, & a bunch of reading on this site.

A little backstory on the situation:
I've had the tractor since '93. It's been a tank- never any serious problems. I use it for shredder work mostly. No loader on it, just a basic ranch utility tractor.

I was running my 6' shredder in some really thick, tall grass & light brush. It would bog the shredder down on occasion. Push in the clutch & let it wind back up & keep mowing. Well, it bogged down & then wouldn't engage again. PS went out & 3 pt wouldn't lift anymore, either.

Changed the fluid (303, 10 gallons) & replaced filter & sump screen in trans, & filter in front mounted pump. Still not working. Started it with the front pump still open during the filter change, & no fluid came out at all. The counter man at the JD place told me to check the splines on my coupler to the front pump (driven off of the crank). Tore it down & it seems to be spinning the shaft fine.

My main question at this point is: should there be any resistance when spinning the front pump shaft? I can spin it very easily, & in my way of thinking, it's a pump- it should have some restistance to it. But it spins like a tire on a wheelbarrow.

And another question I have is: does the front pump draw the fluid from the trans, or does the trans pump push it to the resivoir?

 

[Tx Jim]

Welcome to TBN
What type pto continuous(dual stage clutch) or hyd ind??? Trans pump must supply oil to frt pump IE frt pump has no suction. With hyd filter cap off,container under opening turn over engine for 15 seconds and measure amt of oil pumped out in container. There should be a little over a gallon. IIRC spinning pump shaft should have a little bit of resistance as one is moving 8 pistons in/out BUT it's been since the early '80's since I've been real close to hyd pump. It's possible filter relief valve in trans case or stroke control valve in frt pump isn't closing correctly.

 

[46stude]

Thanks for the welcome and for the assistance.

Dual stage clutch, I believe. Push the clutch in part way, the machine stops moving. Push it all the way & the PTO disengages as well.

Hyd filter cap off... do you mean the main filter under the machine, or the little filter in the front pump?

Oh, and another thing I forgot to mention is that the trans still shifts thru forward & reverse gears fine. Parts man thought that indicated the trans pump still functioned.

 

[Tx Jim]

Main hyd filter on RH side of trans case. Does your tractor have a fwd-rev(rabbit-turtle) lever on the LH side of steering wheel?

 

[46stude]

No lever on the left. It has the throttle on the right, then down below are the two shifters. Park, reverse, hi, and low to the left, then the 1-4 (& 5-8) shifter to the right. PTO lever below the seat, left. 3pt lift lever below the seat, right.

I will get over there and try the filter removal/ fluid test when I can.

 

[Tx Jim]

If your tractor has no lever on LH side of dash then hyd's or lack of hyd's will not affect trans shifting or tractor self propulsion in any way EXCEPT trans pump does lubricate trans shafts/brgs.

 

[46stude]

And that's why its parked at the location still. I didn't want to risk any damage by driving it back to my equip yard.

I did get by earlier this evening & try the procedure. Yeah, I knew there was a problem when I removed the filter. It was still dry! Cranked the machine & a little dribble came out after I stopped.

Filter relief valve, maybe? How bad a job is that?

 

[jd110]

Since you lost pto, that indicates the splines on the pto disk are probably stripped or shaft is broken. On the 2 stage clutch, no oil pressure is required to engage pto, but the sme shaft from clutch to pto drives the transmission oil pump. If you remove the round plug from left side of clutch housing you should be able to see the shaft and clutch hub. Put the pto in gear with tractor off. You should not be able to spin pto by hand. If you can, have someone turn it while looking in clutch housing inspection hole. The hydraulic pump is spinning easily probably because it is dry with no oil being supplied to it.

 

[46stude]

Thanks, I'll check that out tomorrow sometime.

 

[Tx Jim]

Since you lost pto, that indicates the splines on the pto disk are probably stripped or shaft is broken. On the 2 stage clutch, no oil pressure is required to engage pto, but the sme shaft from clutch to pto drives the transmission oil pump. If you remove the round plug from left side of clutch housing you should be able to see the shaft and clutch hub. Put the pto in gear with tractor off. You should not be able to spin pto by hand. If you can, have someone turn it while looking in clutch housing inspection hole. The hydraulic pump is spinning easily probably because it is dry with no oil being supplied to it.

Very good point jd110 about stripped splines on pto input shaft!!!!!