Zetor Crystal 8011 Hydraulics

The 3 point linkage and spooler were working fine when I parked up a week ago on a slope with the tractor nose up above the rear wheels.
On trying to use both functions today neither would work but the PTO is working.
I have tried the fill up with oil and point the front downhill on the steepest slope I could find and rev the engine hard but this has not succeeded.
As nothing was moved or touched when parked up initially I am assuming an air lock of some sort. Has anyone any suggestions how to get my hydraulkics back? Incidentally I have undone the union nut for the spooler valve feed so there is no back pressure on the pump and it could start working with no load.
Getting desperate as getting into the hyraulics frigfhtens me to death, and I will tackle most things!!
John M Zetor

The PTO is a totally seperate system from the hydraulics.
Make sure the pump is in gear.... Its the lever on the left side of the clutch housing.
Is the main hydraulic filter clean, its the large ally one under the left side floor on the side of the gearbox, park the tractor left side uphill and remove and wash in petrol.
Then try the head down a steep hill trick. If it still doesnt work then try slackening the large, I think its a 32mm spanner, bolt through the banjo where it comes out of the hyd pump, with the engine running to vent any air.
If your tractor has a second spool valve, that's one with a lever to the left of the seat. then it may be easier to slacken one of the joints on the flexible pipe leading to it from the pump.
You can also try adding an extra 5 litres of oil to the gearbox, but if you do this its a good idea to reduce the level once its working since it can cause oil leaking onto the brakes if the seals are not good.
Hope this helps, Dave

If Dave P's suggestions don't work, find the hydraulic supply line on the left hand side of tractor near the top of the back axle as you are standing at the back of the tractor. There is a banjo bolt you can crack open there. This has cured many airlocks for me.