806 steering/mcv problems

I am having issues with steering on our 806. It has started cavitating very bad when you steer the wheel. It also has started to not move when letting out the clutch. I was wondering if a seal in the mcv pump might have gone out or what i should be looking for. Any help would be great

I would try to adjust the clutch for that. The steering check the fluid level then the filter first. Then check for leaks in the steering lines. If it is truly cavitating your starving the pump for oil.You will need to inspect the filter area for bad a bad o-ring and gasket around the screen and filter cover. It has been a long time since I had problems with ours. There is a valve body that screws in to the MCV and it controls pressure and flow. It seems to me it was in from the back about half way down.

pulled pump and put a differnt one in. now no oil pressure. I am wondering if it is starving for oil. The passage for the Oil for the pump comes from the Filter Right?

You have three problems, none of them critical, but combined will cause the symptoms you are having. The O-ring seal between the center section and the rear frame is leaking air into the hydraulic system suction side. It is located above the normal oil level in the transmission so it will leak air in rather than oil. Quick fix is to run the oil level about 5 or 6 gallons over full. That puts the oil level above the leaking O-ring so it will now draw in oil rather than air.

This problem is made worse by a worn MCV pump. A new pump is somewhat forgiving oh having to pump air but a worn one does a poor job causing the loss of hydraulics for the steering and controls.

The third problem is the sprag clutch is worn out in the low side of the TA. It most likely already slips under load. Without any hydraulic pressure to engage clutch packs in the TA all you are left with is the mechanical side of the low side clutch. Since it is worn out the tractor does not move when there is no hydraulic pressure.

First try adding the extra oil. If that is not enough to get you going, this is how you can bleed the air from the system. Remove the small plug on the back side of the MCV assembly. It is the one with the 5/8 inch head. Start the tractor and be ready to shut it off when oil shoots out. If you get no oil with the tractor idling you can apply some air pressure to the oil fill tube to assist in the bleeding.

I think it is actually a filter issue. we had to replace the gear that drives the mcv pump and the gear the the parking break goes into. I think that the oil got water into it and the filter got plugged. It actually colapsed the filter. Will let you know if it fixes the problem. I don't think it is the pump or the o ring. The o-ring was replaced when we did the gears. and I have tried a new pump with no success.

Might try using compressed air to prime the system. Just start engine, place lift lever in the up position and blow air into the dip stick hole. If you have a weak pump or an O-ring leaking this should help prime the system.