Cupboard wrote:

It did until I adjusted it properly

The nut that holds the piston in should be tight and not move. If it "needs" to move to make the carrier work then you haven't got the hinges lined up properly. What I did was assume that when the door was open and the carrier was out at 90° to the back of the Defender the piston would be in the correct position in the slot.

I made a note of where that was, then closed the door and saw which way it went. From there, you can work out which direction you need to adjust the hinges in. For example if it's at the top of the slot when the door is open but at the bottom of the slot when the door is closed then the top hinge needs to go out (left, away from the door) to lift the bolt when the door is closed.

Once you've worked out which way they need to be adjusted, open the door and tighten the piston-nut up nice and tight. Then loosen the sideways adjustment bolts (I think they're the top hinge) and close the door. You might need to loosen the other hinge too. Once you've done that and it's closed happily, tighten it all up again and it should open and close without the piston trying to move up and down.

Ahh that makes sense! Thanks for the reply.

I'll have a play this afternoon and adjust it properly