PT 1850 mower stopped suddenly.

[BWSwamper]

Mowing today and the PT1850 mower stopped suddenly. It just spun down and stopped.

Blades and hydraulic mower motor turn freely.

At first I suspected PTO electric issue, but then noticed slight to moderate engine rpm drop when PTO switch was turned on.

No significant new leaks.

Any suggestions?

 

[ponytug]

When you switch the PTO ON/OFF,

• Can you see a change in the fluid flow in the tank?
• Does the hose to the mower flex?
• Can you feel the mower motor spin?

My guess is that the motor to mower coupling broke. Which mower are you running?

All the best,

Peter

 

[BWSwamper]

Thanks. This is with the 7 ft. three spindle Brush mower.

I'll check those all those items tomorrow.

I thought I saw the mower motor sitting still, but i was really just looking at the coupling. If the finger coupling broke I could have missed the top spinning.

Could you clarify what you mean by the mower hose flexing? These are pretty large diameter and don't pulse much when engaging normally.

The broken coupling fits with the timing of the event. I was mowing along a bank in a pasture with 2 1/2- 3 ft. Fescue and had just knicked a root.

 

[agjones]

If the coupling looks OK externally... Could be the set screw/key on the coupler.

 

[MossRoad]

Usually when I flick on my PTO switch, even at low engine rpm, the hoses to the mower will flex.

That's a good test to see of fluid is getting to the hoses.

 

[MossRoad]

If the covers are still on the belt and pulleys, look for a broken belt, too.

 

[BWSwamper]

Thanks guys. I'm going to be investigating all those issues this afternoon. I'll report back.

 

[BWSwamper]

Upper and lower halves of lovejoy coupler both fixed to their respective shafts. Hydraulic mower motor shaft can be rotated by turning the coupling.

Mower belt intact and all spindles turning easily simultaneously by moving belt by hand.

Rpm drops slightly when pto engaged.

3/4 inch main mower lines don't pulse or flex when pto is engaged, but I don't remember noticing much of that before as they are pretty stff and lay over the top frame mount of the mower.

 

[agjones]

Stuck relief valve?

 

[BWSwamper]

That was my next question. That was the only thing left on the Service FAQs for PTO not working. ("Trash in relief valve"). Except for a bad pto pump, but this pto pump hasn't made any noise and isn't leaking.

Where is the relief valve in question located, and how would one clean it out?