mrb2872

I'm upgrading from manual to power brakes on my '71. I'm curious on what the correct factory finish is for the master cylinder and booster. I would have expected yellow zinc, but I'm seeing a lot of variances on Google searches of 'original' engine bays. Black, grey, more of a silver. Maybe it was a lottery of whatever was in the bin that day for the guys to put on at the factory?!?

I was looking through a bunch of the other threads about this change to make sure I've got what I need. It sounded like just adding the booster to and reusing the existing master cylinder was ok?

Thx.

VC455

The booster was finished in zinc dichromate. This gives a rainbow look to the surface.

It's not a durable coating. If you have a fluid leak, the dichromate will not prevent rust.

What I found to work well is to plate first with nickel and then do dichromate for the final layer. That way the booster is protected from rust and the dichromate stays looking fresh.

70Post

The dichromate that Gary mentions above will be a gold or "yellow" color/tint. It'll probably be a lot brighter and "colorful" compared to the plating on an original booster but it will be considered "correct" IMO. Black or silver.....no. Black is indicative of possible auto parts store replacement booster (cheap finish to keep the price down) and silver isn't correct for your era. It wasn't a "that's what's in the parts bin" situation as you mentioned in your original posting.

As far as the master cylinder.....black or cast iron. I say black but others may argue bare (which would be a cast iron paint if rust is a concern). Cap should be dichromate (ie - yellow/gold).

Can you post a good pic of your current master cylinder??? Can you see if it has a two letter code stamped into a machined half-circle-or-so pad on the "nose" of the master?

mrb2872

I'd take a pict, but it's up at a shop getting some carb work done. Thanks for the confirmation.