hydraulic system for 3 point 861 ford

Hydraulic system will not lift the 3 point5 foot bushhog mower high enough . Installed stay chains to keep the mower at proper height for mowing. Is there a port for installing a check gauge to check the hydraulic pressure of the hydraulic pump? What should the hydraulic pressure be? Hydraulic cylinder under the differential cover that operates the 3 point. How is this cylinder checked?
Would appreciate information on how to check the hydraulic system and what others have generally found to be problems with the system on a ford 861 Have several other tractors; ford jubilee, 8N, TE 20 Ferguson, John Deere 850;hydraulic systems on these tractors lift the 3 point implements perfectly.

I would not waist my time pressure checking until I confirmed it will lift all the way...

What I have to say about it....

http://forums.yesterdaystractors.com/viewtopic.php?t=1218671&highlight=screwdriver

Hobo, NC

Thanks for the information on the hydraulic system on a 861 ford. Will remove the hydraulic fill plug and check movement of the valve

Heres some info posted by ZANE-----------If it is determined that the pump is operating right and supplying enough volume of oil under pressure to the hydraulic system then you may have a sticking unloading valve in the lift ram cylinder housing.

If the lift is jumping/bumping/hiccupping it is caused by the lift trying to hold the height constant with a leak internally of the hydraulic system. The leak must be fixed before these symptoms will go away. Common leaking places are the ram cylinder O ring/s, the pressure relief valve, the O ring on the unloading valve or a blown gasket under the ram cylinder to housing flange surfaces.
On the 53 and up Ford tractors there is a gadget named the unloading valve. It is hydraulically shifted by the movement of the control valve. The control valve does not actually move oil to the ram cylinder. The oil is directed to the ram cylinder by the position of the unloading valve. The Hundred series has the same valve in a slightly different form but performs the same function.
If and when the unloading valve stops moving then the lift won't lift until the problem that is causing this condition is fixed.
A faulty back pressure valve can cause the unloading valve to stick.
The unloading valve can stick on it's own.
The unloading valve has an O ring that can become worn until it will not allow the valve to move.
The pump could have lost it's prime too. The piston pump must be bled by opening the front head plug in the pump and running the engine slowly until all air bubbles are gone from the escaping oil. Stop the engine, replace the plug and start the engine again to see if that fixes the problem. It can! -----------Someone also said to use the OEM Ford oring on the unloading valve or you'll be sorry.

Rverroadrat,
Thanks for the information to check the hydraulic system on the 861

The hydraulic system in the 861 we are working on doesn't lift implements high enough. The system additionally creeps down so we used stay chains to set the bushhog at the proper height. The system barely lifts the 5 foot bushhog off the ground
Hydraulic fluid is full