4020 powershift pto turns all the time

[wore out]

I got no issues slipping in gear and everything shifts good it’s just the clutch don’t stop the tractor and holding the clutch and you rev it up it’ll go forward. But yesterday I went to crank it and found a awful leak someone had brazed in the past and the line crushed right behind the frame rail that runs From the pump at the front to the valve at the clutch so I pulled frame rail and got it out to change it today. Someone mentioned checking pressures could someone Tell me which ports do what and what pressure should be?

The line you found damaged carries oil FORWARD to supply the main hydraulic pump.

The powershift and PTO clutches and PTO brake are operated by the transmission pump built into the front of the transmission, much like a conventional automatic transmission pump.

There are 3 ports in the clutch valve and they're marked for clutch, PTO clutch and PTO brake. Pressure should be 140-160 psi when the function being checked is "active".

In addition, the shift valve on the RH side has about 7 pressure check plugs where the pressure to a specific clutch or brake pack can be measured.

 

[used red MN]

The line you found damaged carries oil FORWARD to supply the main hydraulic pump.

The powershift and PTO clutches and PTO brake are operated by the transmission pump built into the front of the transmission, much like a conventional automatic transmission pump.

There are 3 ports in the clutch valve and they're marked for clutch, PTO clutch and PTO brake. Pressure should be 140-160 psi when the function being checked is "active".

In addition, the shift valve on the RH side has about 7 pressure check plugs where the pressure to a specific clutch or brake pack can be measured.

See what it says in the paragraph 6 in his photo. Sometimes something like low fluid etc. can allow the clutch packs to slip under load. This warps or distorts the steel plates and lined plates in them so they won’t or can’t release as they would normally, then they “drag” only way to fix that is to tear it down and replace them.

 

[Joe ellis]

See what it says in the paragraph 6 in his photo. Sometimes something like low fluid etc. can allow the clutch packs to slip under load. This warps or distorts the steel plates and lined plates in them so they won’t or can’t release as they would normally, then they “drag” only way to fix that is to tear it down and replace them.

after useing it some today the clutch and park has gone to working could the pto clutches stick from sitting?

 

[used red MN]

after useing it some today the clutch and park has gone to working could the pto clutches stick from sitting?

No, clutch packs running in oil can’t really stick like a dry clutch.

 

[Joe ellis]

No, clutch packs running in oil can’t really stick like a dry clutch.

well there was some water in The oil today when we drained it so that’s why I’m wondering if they could of stuck from sitting in that water

 

[Scott 730]

Define the quantity of "some water". Are you talking clear water, or a water/oil emulsion? Water is not good in any wet clutch/brake environment. If it was mine, I would be draining oil, clean sump screen, change both filters, refill and run for a while. Drain, change filters, and refill again. And use ONLY J20C rated oil!!!! None of that yellow bucket 303 swill!! If the bucket doesn't say J20C DO NOT put it in a Powershift tractor, or any JD tractor for that matter.

 

[Joe ellis]

Define the quantity of "some water". Are you talking clear water, or a water/oil emulsion? Water is not good in any wet clutch/brake environment. If it was mine, I would be draining oil, clean sump screen, change both filters, refill and run for a while. Drain, change filters, and refill again. And use ONLY J20C rated oil!!!! None of that yellow bucket 303 swill!! If the bucket doesn't say J20C DO NOT put it in a Powershift tractor, or any JD tractor for that matter.

it was a water/oil mix. I changed both filters cleaned screen and filled it back up with vp racing j20a equivalent and Lucas hydraulic oil booster we been running that oil in everything for prolly 5 years never no issues it’s 10x better than the superior brand everyone else sells we‘ve had bad luck with it we also used a carquest equivalent for prolly 10 years but it’s gotten hard to get. what’s the difference between j20a and j20c?

 

[Tx Jim]

JD hyd oil originally was named 303 but when government outlawed using sperm whale oil then name was changed to Hy-Gard. Over numerous years Hy-Gard spec's have been changed from J20A to J20B to J20C to present day J20D. Different additives has changed spec's over the years