PTO no power

[stockcrew]

I have a Zetor 8245 and the PTO shaft switches on and off. When on it turns but has no power. Does this indicate a fault with the hydraulic pump? Are there test points for checking the pump pressure/s? This tractor had very little oil in the transmission (less than 20 litres) when I purchased it. The previous owner declared the PTO problem and indicated he had not tried to fix it. Cheers

 

[dave_peters]

At the rear of the tractor on the R/H side you will see 2 pipes that go into the side of the rear casing near the PTO. If you remove one of these pipes and put a guage on it you should have a pressure of 175 PSI or 12.5 bar. If there is no pressure then move the PTO lever the other way and there should be pressure. One pipe is engaging the PTO and the other is braking it.
If the pressure is OK then you will have to remove the PTO pack, which is done by undoing the ring of bolts around the PTO, after you have dropped the hitch (if fitted).
Then check the 3 O rings round the pack
The pack is taken apart by removing the very large circlip and lifting out the contents where you will find a cuff seal which you need to check. also make sure the plates havn't been worn out by constant slipping. Then you need to have a press and push apart the centre from the bearing at the front. Inside you will find 2 metal "piston rings". If the pressure is OK and the cuff seal is OK then the problem will probably be a broken ring.
Replace and re- assemble.
If the pressure is not OK then the TA and 4WD wouldn't be working well either as they share the pump.

 

[dave_peters]

Following on from the previous post, the TA/PTO pump is situated on the rear of the clutch housing/gearbox bulkhead and cannot be removed without splitting the tractor.
The control box is under the floor ontop of the gearbox and contains the relief valve which can be checked.

 

[stockcrew]

Thanks Dave, I haven't tested the things you suggested yet but I will and report back. At the moment I have developed an electrical fault and the tractor wont start. It just makes an electrical contact rattle in the box under the seat - might just be a voltage thing.
Cheers, Wayne

 

[dave_peters]

Check your battery terminals !!

 

[stockcrew]

Hello Dave, We knew we had a toggle switch instead of the normal key switch but on inspection of the wiring there have been mice eating it. I notice with another post last year you were able to supply a wiring diagram to an owner in middle Germany.
Would you have and would you be willing to supply me with an electrical schematic for the 8245 (before I get an auto electrician)
Kind regards
Wayne

 

[dave_peters]

Sorry, but I havn't got a useable wiring diagram for the 8245.
I only have one for the 8045 and i think there are a lot of differences between the two, especially as it seems yours may have 24 volt starting since you have the "box under the seat". this is only found normally on 12245 in the UK.

 

[ben21799]

wondering about L shaped seals inside pto i can only see one
was told there are two .also have one split cluch disc
Q what can go wrong with relieve valve (looks fine )
thanks