late 4020 PTO o-ring leakage

[bv]

can someone explain the cause of the leaking o-rings on PTO pistons and how to get the adjustments right when they have to be replaced and did they have any upgrades for these problems? I have a buddy having this issue on his late 4020 and had to replace the clutch because it was oil soaked. Was the PTO setup better on the older 20 series because I have a 64 model 3020 power shift that can be used to mow with if needed. I have 2 late 4020's a late 3020 and a 2520 that we use to pull a bushog some so I'm trying to do my homework before we have to tackle this repair. Thanks again.

 

[Tx Jim]

I've read where folks put extra o-ring on the 2 plungers that operate pto on '69-'72 2520/3020/4020 Syncro-range pto control valve.

Tractors with Powershift have a different design operated pto. Powershift clutch is a hyd/wet clutch & PS pto brake has a long history of failure. '64-'68 2510/3020/4020 Syncro-range has dry mechanically engaged dry pto clutch & '69-'72 has hyd engaged dry pto clutch.

 

[bv]

I've read where folks put extra o-ring on the 2 plungers that operate pto on '69-'72 2520/3020/4020 Syncro-range pto control valve.

Tractors with Powershift have a different design operated pto. Powershift clutch is a hyd/wet clutch & PS pto brake has a long history of failure. '64-'68 2510/3020/4020 Syncro-range has dry mechanically engaged dry pto clutch & '69-'72 has hyd engaged dry pto clutch.

I watched a video where the guy installed the o-rings with the white plastic rings then installed the 2 plungers and the turned the housing over and put 2 more o-rings on the rear of the plungers, is this what you're talking about? Where do you measure and make the correct adjustments?

 

[matthies]

You have to adjust the valve on the dash, make sure plunger is bottomed out when engaged. Replace the piston housing, they are available aftermarket.

 

[Glen D Anderson]

can someone explain the cause of the leaking o-rings on PTO pistons and how to get the adjustments right when they have to be replaced and did they have any upgrades for these problems? I have a buddy having this issue on his late 4020 and had to replace the clutch because it was oil soaked. Was the PTO setup better on the older 20 series because I have a 64 model 3020 power shift that can be used to mow with if needed. I have 2 late 4020's a late 3020 and a 2520 that we use to pull a bushog some so I'm trying to do my homework before we have to tackle this repair. Thanks again.

We've been lucky with our '72 4020. The PTO pistons have never given us any trouble. We've just resealed them whenever we've had it split to work on the clutch.

IMO the system was an answer in search of a question. In use, our PTO has never been easy to feather the engagement / start up even with the valve set per the SM. Our older 20 series are much more user friendly. Not sure if our tractor is the exception but I've never been impressed with it.

 

[matthies]

Before teardown, start tractor and pto, then lay under the tractor remove cover and look at the pistons, they should NOT be moving, if they are, valve is out of adjustment.

 

[620 John]

For side console new gen syncro tractors there was a service bulletin years ago on adding a check valve in one of the oil line fittings going to the control valve. Unfortunately good ole Deere and Co. no longer supports the link to those old service bulletins . Maybe someone out there has that bulletin????

I myself have added a second o-ring in the o-ring groove where there's originally a plastic back up ring. Don't remember there being any other place to install more o-rings.

I haven't run into it myself but I know guys have had to replace the operating valve itself to fix the leak. Spendy valve though......

 

[Tx Jim]

I think this is the JD bulletin you referred to.