Here's some info I found on this......
Oliver 550 3 point hitch
I have a 1968 oliver 550 and whenever I have and implement attached to the 3 point hitch it drops down about an inch and then raise and keeps repeating. I have tried to adjust the long nut under the seat and tried the top link in all three holes with no success. Also it does leak some Hydraulic fluid around the two top arms. Any info would be greatly appreciated Thank you.
Re(1): Oliver 550 3 point hitch
This "cycling" is normal. However, if it gets to be too excessive,it probably needs a new O ring on the lift piston. But even with everything fine, it will do this. If you have leakage around the 2 top arms, first check the breather on the unit. If the breather is not plugged, you'll probably have to install new seals on the lift arms. The rock shaft does have bushings that can get worn enough that they have to be replaced also. Larry