856 hydraulics

[cstrucks]

I have a 856 that the PTO has been acting up on. sometimes when you engage the lever it won't take off. seems worse when hot. Once it starts it works fine and doesn't seem to slip. Anyone had this problem? Looking for ideas on whats going on. Thanks

 

[DeltaRed]

Low hydralic oil can effect pto funtion. Pull dipstick and check transmission oil first.

 

[used red MN]

Just FYI the PTO has its own pump and operates completely independent of the tractors main hydraulic system.

 

[Mrfred54]

Clutch pack probably worn out, takes a few seconds to build pressure to lock up the clutch pack. Could also be the suction screen partially plugged and loose in the retaining clamp. Small plug on the left hand side of pto unit is for checking pressure. Adjust pressure by tighten the square nut on to of the spool. Spool has small hole for turning into the square nut. I use a small Allen wrench that fits the hole to turn the spool

 

[caterpillar guy]

After checking oil level and then remove the little plug on the side of the IPTO unit under the lever. There is an adapter for adding a gauge to it you can then check the pressure. That adapter is/was available from your local stealership for a rather pricey price. You need it to be able to put a gauge in there to check the pressure . It should be in the 230-250 range I believe without looking in the book for that. IF pressure is low the valve stem turns in to lift it more . Doubt it is to high and there may be seals leaking in the clutch pack causing low pressure also. Checking pressure and oil level are the cheapest and easiest things first. If the PTO has to come out be very careful not to bend the screen on the pickup tube when removing. with the top or third link off you can reach to hold the drive shaft in place as the unit is removed so you don't have the sahft to deal with at reinstallation time.