PT 1850 mower stopped suddenly.

[BWSwamper]

If I've got things straight, these are the two relief valves on the top of the PTO control valve assembly on the right side of the chasis as one faces the front of the machine.

I guess the cleaning procedure is just remove them clean them out with something like WD40 and reinstall.

Is it okay to use starting fluid as a solvent in this case?

 

[ponytug]

Any non-aqueous solvent should be fine. Brake cleaner would be ideal because it is more forceful, and you can blast any trapped trash out of the relief valve/housing. Check the spring on disassembly to make sure that it didn't crack. (Rare, but it happens)

I hope that fixes it for you.

All the best,

Peter

 

[agjones]

The couple times I had this issue on different equipment, I never saw the suspect. But checking the relief valve and cleaning it solved the problem. So don't necessarily expect a gotcha moment.

+1 on the brake fluid. It's gone by the time you reassemble.

 

[woodlandfarms]

If you aren’t bogging the engine it’s probably a relief valve. My engine will pull through but you do notice a drag when the pto solenoid is engaged.

 

[BWSwamper]

Turns out the problem was that the PTO solenoid/plunger was bad. It was still making a clicking sound when energized, but apparently the plunger got hung up and wasn't opening. Terry at PT said it is rather unusual for that unit to fail suddenly, but that is what it was.

Thanks to everyone for the suggestions and tips.

During the process I did learn a diagnostic trick from Terry. In a similar situation, you can swap out the pressure release cartridges even though they have slightly different settings. One governs the PTO and the other the steering. So, if you've got steering and you swap out the pressure release cartridges and you still have steering, the pressure release cartridges are probably okay.