Hello All - I have a 1989 Land Rover 110 that originally had a 2.5 TD engine in it but which is now powered by a 200 Tdi. I'm replacing the brake master cylinder, and note that when I withdrew the cylinder from the servo, it had a rubber sealing ring around the base of the part hat inserts into the servo. However, the replacement master cylinder I have did not come with a sealing ring.

Looking at various LR parts websites, I don't find any master cylinders with rubber seals to go between the cylinders and servos, and both those parts are sealed units anyway, so my assessment is that there normally isn't a sealing ring between them and that a previous owner added one on my vehicle at some point for whatever reason. Can anyone advise me on this? Am I correct that there isn't normally a rubber seal between the master cylinder and servo on a 110/Defender.

Thank you.