Convertible top frame setup/ fault finding

[BRB62]

I have just finished rebuilding my cars convertible top frame. Stripped completely, repaint, rechrome hinges with new S/S rivets. New pump, hoses and cylinders. Prior to refitting a new vinyl top I am in the process of setting it all up to operate correctly.

After building it up on the car and manually operating without the cylinder rams attached, I aligned it OK. Today I set up the hydraulics, bled the system (Dex III ATF) and operated it but have a couple of issues that so far I have been unable to find any answers to. Hopefully someone can help?

Firstly the mechanism "binds up" when trying to raise from the fully lowered position. Minor assistance by lifting the header bar slightly eases this immensly. Is this just because I am operating without material and so the top lowers too far and kind of overcentres? Once it starts moving it operates OK.

Secondly the right side operates differently to the left. When fully lowered it "springs" back up about 1" and when rising it seems to move faster than the other side and hits the windscreen top early. I have tried rebleeding the system but no change. The top now tends to swing left and I am having a lot of trouble bringing back the alignment. I have tried adjusting the stack height.

Thirdly the top will not hold position when partly raised but slowly drops as if pressure is being bypassed somewhere- there are no leaks. Initially I thought the cylinders but clamping the hoses did not make any difference, now suspect the pump? Fluid level is OK, bottom of fill hole as per instructions. If I drive the top to fully raised position it slams down hard onto the windscreen top, to prevent this I have to stop the motor about 2/3s into its travel (past fully vertical position) and it will slowly drop down all the way to the windscreen.

A very frustrating day. Will have another look tomorrow (and the next etc) but with any luck I can get some helpful pointers as to what I may be missing?

Thanks

Rick