Topic: Master Cylinder Reuild...secondary cup

[SHELLFISH]

I'm looking for some tips or tricks on a master cylinder rebuild.
It's off a 1976 550K but I'm sure the 750's or a different year are all the same.

I see that you have to get the secondary cup over the piston. The cup has a center hole of 6.5 mm while the piston has an end flange of 14 mm! I sure don't want to tear the cup getting it on.
The only thing I can think of is to try warming it first in a cup of hot water and then lue it up with brake fluid and try slipping it over quick.

I've tried a search. looking at posts and videos and the manual. No word about this chore!
Any help is appreciated!

[Simpson]

I just did a rebuild about 10 days ago. It took about 10-15 minutes.
My personal advice tips:
1.) When slipping on rubber seal on the piston, lube parts well with Armor All, should slide right on
2.) Make sure you have the correct long nose pliers intended for the inside larger snap ring. The snap ring for the rubber boot comes right out the one behind it can be tough without the correct tool.

[Don R]

I lubed with silicone grease. Went right on. OK so far.