solved Zetor 7745 Hydraulic and PTO not working.

Hi folks,

Got a 1990 7745. Yersterday morning I used pto with post hole digger without problems, then in the afternoon I was doing fencing with front loader without problems. Suddenly front loader hydraulic stopped working with crying noise from possibly the pump when trying to lift. 3 Point arms were still lifting for a few minutes then nothing. All that happen WITHOUT playing with pto clutch lever or the floor lever to switch hydraulic.

Actual symtoms are;
-Pump seems fine, nothing broken, teeth good, no metal accumulation and not loose or too hard to turn by hand.
-The magnetic filter was muddy but I think it had not been cleaned in a while...
-PTO sometimes turn a little when engaging the PTO manual clutch lever all the way (Weirdly).
-Very little to no lifting power on 3 Point hitch,
-No front loader movement.
-In addition before this problem happen, the 4th position of the floor lever (Hydraulic only) never really worked, PTO always turned a little...
-Tractor driving is un affected (clutch, brake, transmission all good)

I think it might be related to the Hydraulic / PTO engaging lever on the floor or the manual PTO shaft and hydraulic lever by the seat. Because the PTO doesnt turn and to my knowledge the PTO doesnt need the pump gears to work...?

Any clues where to start what to look for ? I heard there is access panel to verify the levers but I dont know where its located...

pmcote said:

PTO always turned a little...

Click to expand...

Thats normal - this is due to the drag effect of the oil.

What happens if you turn off the engine, turn on the PTO and hydraulics and then try to turn the back of the PTO stub with pliers?
Normally it should not be able to rotate, if it does, there is a problem with the drive (clutch, for example).

It might be a stupid question, but I'll ask anyway:
- PTO speed is preselected? So 540 or 1,000 rpm?
- is the left of the two short levers in front of the seat switched all the way down?

Joachim said:

Thats normal - this is due to the drag effect of the oil.

What happens if you turn off the engine, turn on the PTO and hydraulics and then try to turn the back of the PTO stub with pliers?
Normally it should not be able to rotate, if it does, there is a problem with the drive (clutch, for example).

It might be a stupid question, but I'll ask anyway:
- PTO speed is preselected? So 540 or 1,000 rpm?
- is the left of the two short levers in front of the seat switched all the way down?

Click to expand...

Hi there thanks for your reply,

The 540 is selected , I also tried on 1000. The left floor lever is all the way to the front. One noticeable thing is there is no grinding when this lever is moved to PTO and hydraulic when engine is running and manual pto clutch not engaged. I also took a picture of the inside of PTO clutch view port, Im usure if those lifting tabs are right.

pmcote said:

Hi there thanks for your reply,

The 540 is selected , I also tried on 1000. The left floor lever is all the way to the front. One noticeable thing is there is no grinding when this lever is moved to PTO and hydraulic when engine is running and manual pto clutch not engaged. I also took a picture of the inside of PTO clutch view port, Im usure if those lifting tabs are right.

Click to expand...

The PTO always turn by hand what ever the floor lever position is. I did not try with the PTO Clutch lever engaged... I should.

Update, for you folks , it was the clutch assembly disk. The splines were all gone. All fixed now !