I have never been real fond of these '65 on up three cylinders. Sorry JMOR. And after today I have definitely not changed my mind. Original problem was the hydraulic pump was missing a pin and spring behind the exhaust valve plate. Looked like the pine was beat to the bottom.. In trying to fix the problem I managed to pretty much destroy the head of the pump. Called a salvage yard for a used head ..They sent one and got it today. It is a new after market head casting. with roll pins for check valve stops already in place. Apparently these newer piston pumps have a cage affair holding the springs and check valves.in place. Never have seen that in a hundred series piston pump. Had to grind the tops of the cages a little so as to fit deep enough for the valve plate to fit. Figured that out after installing the pump with still jercky action, not air. After the "fix" job put the pump back on and still have the same problem with jercky lift arms, not air. Have a hose from the bleed plug to the reservoir. Going to let it set a few days. we are going out of state for a few days. Will deal with it again when we get back.?????.@#$%$#@