Thanks jp928, I have two delay units that fit to the motor, both working fine. Yes I’m talking about the control valve on the steering column, I‘ve had a search but can’t find a replacement valve. I think that the white valve must be pressed into the black body somehow, and not designed to be removed at all. But I also need to check the tube fitting, it only needs to be very slightly loose and vacuum will be lost. I’ve already repaired a poor fit at the motor end with silicon tube, so will probably do the same at the control valve end. The original plastic tube is now quite rigid so is no longer a tight fit.