oldnslo
Super Member
Not familiar with particular jack but there shouldn’t be any check ball in the return flow from the lowering screw. Also shouldn’t be any pressure on pump handle piston so sounds like still assembled incorrectly.
The way I would approach this is study the oil flow paths.
1) from reservoir into pumping piston. There needs to be check that allows oil into the pump and blocks it from going back into the reservoir.
2) from the pumping piston there needs to be a check that allows oil into the lifting ram and prevents it from returning to the pumping piston.
2a) the pumping piston should also connect to system pressure limit or relief valve. Low pressure side of relief should connect to tank.
3) need a flow path from lowering valve to reservoir. Should be no restrictions in the tank side of lowering valve.
The way I would approach this is study the oil flow paths.
1) from reservoir into pumping piston. There needs to be check that allows oil into the pump and blocks it from going back into the reservoir.
2) from the pumping piston there needs to be a check that allows oil into the lifting ram and prevents it from returning to the pumping piston.
2a) the pumping piston should also connect to system pressure limit or relief valve. Low pressure side of relief should connect to tank.
3) need a flow path from lowering valve to reservoir. Should be no restrictions in the tank side of lowering valve.