Mowing Finish Mower Not Working

[tlb]

I used my finish mower yesterday and at first it work fine. I turned the PTO off to move from the back yard to the front yard. When I turned the PTO switch on again, the I could hear the PT425 engine under load but the mower blades did not spin. I turned the PTO switch on and off several times but the mower blades failed to spin. I turned off the PTO and spun the blades by hand and everything was free and loose. I switched the mower out with a tiller and everything worked fine when I switched on the PTO.

Does anyone have any idea why the mower (hydraulic motor) is not turning?

-tim

 

[ldabe]

Not sure about yours, but mine has a belt under an enclosed guard.
By chance could it be the belt that turns the blades has broke?

 

[DHS]

Tim,

I had a similar problem two years ago with my PTO solenoid. I believe the ignition switch would heat up and dropped the voltage to the PTO solenoid. When the switch got hot the lower voltage partially opened the solenoid. I bought a new solenoid from PT but that was not the problem. Rather than replace the switch, I installed a wire with a fuse from the battery post on the starter to the PTO switch. No more PTO solenoid problems.

Try the PTO switch after the tractor cools for an hour of two. If it works it may be the voltage drop through the switch.

Keep us informed. This problem has several possible causes.

Dale

 

[BobRip]

Tim,

I had a similar problem two years ago with my PTO solenoid. I believe the ignition switch would heat up and dropped the voltage to the PTO solenoid. Rather than replace the switch, I installed a wire with a fuse from the battery post on the starter to the PTO switch. No more PTO solenoid problems.

Keep us informed. This problem has several possible causes.

Dale

Does the battery run down if you leave the PTO switch on after you shut off the engine?

 

[DHS]

Bob,

I assume it would. But, I have never left it on to find out. I left the wire connections to the ignition switch so if the PTO switch is on the motor will not start. That interlock remains inplace. But you are correct, if you turned on the PTO switch when the motor is off it will energize the solenoid.

Next time I order filters from Jacks small engines I plan to order a replacement switch.

Dale

 

[Bob999]

When I turned the PTO switch on again, the I could hear the PT425 engine under load but the mower blades did not spin. I turned off the PTO and spun the blades by hand and everything was free and loose. I switched the mower out with a tiller and everything worked fine when I switched on the PTO.

Does anyone have any idea why the mower (hydraulic motor) is not turning?

-tim

Because the engine loads when the PTO switch is turned on I believe that the PTO solenoid is working. The PTO pump is pumping all the time and the PTO switch simply reroutes the fluid from a bypass circuit to the quick connects on the front of the tractor. If nothing is connected to the quick connects or there is a blockage in a circuit attached to the PTO quick connects then the engine will load.

The fact that the tiller works but the mower does not, and because the mower blades turn freely, it suggests there is a problem with the motor on the mower or hydraulic lines on the mower.

 

[BobRip]

Have you checked the belts yet? An unloaded hydraulic motor would put some load on the engine.

 

[duane]

Check your charging system rectifier. (I presume your hydraulic cooler fan was running.) If your rectifier is not converting the flywheel coil AC to DC voltage, the hydraulic fan pulls down the battery such that voltage is insufficient to completely stroke the PTO solenoid valve. It strokes halfway and loads up the engine.

 

[tracdoc]

Hi Tim,

We're anxiously waiting to learn what the problem might be with your PTO solenoid and/or mower motor. Have you had an opportunity yet to do any more diagnostics?

Thanks for keeping us posted.

 

[tlb]

Sorry guys, but I have not had time to look at it yet. Since the PTO works fine with the tiller atttached, I am confident it is either in the mower hydraulic lines or mower hydraulic motor. Not knowing squat about hydraulic motors, I was hoping someone had run into this and knew the answer.

The blades turn freely and easily by hand. The belt (around 3 pulleys and the hydraulic motor shaft) turns easily. The hydraulic motor shaft spins freely by hand. So what's left that could cause it to not work?

Is there another test I could do to narrow down the problem? Are there debris screens or filters inside the motor or hydraulic lines? Any help is appreciated.
-Tim