I'm in the process of replacing the Brake Master Cylinder (MC) in my '70 P1800 E and have found some instructions on ensuring the correct clearance between the MC's primary piston "collar" and the brake Servo cylinder's front thrust rod when the brakes are at rest. Unfortunately, I have already disassembled the old MC so I can't look at the old part to see what the original "clearance" might have been (if any) but when I fit up the new MC the thrust rod slightly pushes IN the primary piston. My question is ;
- Is this ok or is there a way to adjust this clearance to have the primary piston sit without being moved when at rest? I've checked the end of the rod and it does not have an adjusting screw. The next option would be to insert thin washers on the bolts between the Servo and MC (I don't like this option...). I'm concerned the piston will not come forward/out enough for the fluid container opening to be cleared.

I'm also looking for a source for the Servo air filter, anyone know where I could find one of these?