Master Cylinder Rust Prevention

[Curtqq]

I'm changing out my power brake master cylinder as part of a long needed cleanup for my 69 Camaro. I am trying to keep everything as original looking as possible without breaking the bank .  I've had the new master cylinder laying around for months and of course it's already showing rust.  I've read about every possible way that people are dealing with obtaining a non-rusted finish.  Most paint options eventually succumb to brake fluid that eventually hits the finish.  I tested a baked caliper paint finish on another surface and it only held up a little better against brake fluid.  I don't like the way that black, clear, or even cast iron paint or epoxy looks, and I don't want to switch to silicone fluid.  I considered maintaining the surface with a rust preventative but I think that would encourage dirt to stick to it. 

I'm just discovering guys that have used Calyx manifold dressing on master cylinders.  It too needs to be maintained to a degree and since it really doesn't dry, it will scuff off a little if touched, which I'm ok with.  Then I read a post that someone just uses anti-seize paste since apparently the manifold dressing is basically a graphite paste.  I rubbed a tiny bit of Never Seize (not the high temperature nickel stuff) on my slightly rusted master cylinder and the rust disappears and the final color is indistiguishable from the bare cast iron.

So has anyone else tried this technique, and is this an effective enough finish that might only need minor occaisional touchups?

[x66 714]

I just paint the m/c with semi gloss black paint & just be careful when adding brake fluid. BTW, the machined surfaces got no paint If you want to know about the new dot 5 & the new offshore rubber seals, I have a horror story for that....Joe

[169INDY]

Sample 346/309 Master Cyl.

[boomer632]

Semi black as stated. They were painted black from the factory. Thats my next project too.

[Curtqq]

Hmmm, now I'll have to reconsider.  I always thought that they were natural finish from the factory, but I see now that Jerry M's book says Semi Gloss black, natural acceptable.  So I guess they did come both ways.  Always liked the natural, but unrusted look, but I guess that's not practical.  Perhaps I'll try the baked finish then. 

Thanks for clarifying.

[boomer632]

He pointed it out in my CHP report.

[169INDY]

What does the "CURRENT" 1969 Legends Judging manual state?

The 1967/1968 Book (Manual) Current States the Casting was and should be Semi-gloss black. No mention of Natural.

It is my opinion that over the Years Service parts from a secondary market or rebuilder were found on "original" cars and Natural was tacitly accepted when this is NOT how they left the factory. Additionally Factory Parts became "Natural" via the damaging prolonged exposure to the Highly paint attacking action of DOT 3 fluids over the years effectively 'stripping' Delco black paint from the castings leading to a Natural look. (i.e. Damage from use and age).

FWIW

JIM

[KurtS]

67-69 MC's were black. It was a cheap paint on an unmachined surface - it didn't hold up hence why natural was thought to be correct.
If you look at a well-stored Corvair, the MC is protected in the front trunk and will be black.

[william]

NOS service 346 master.

[68camaroz28]

Years ago I purchased from Stahl Headers when Jere was going out of business a NOS brake booster/master cyl. assembly built May, 1968. On the GM build of materials it states master cyl. painted black. I know many state semi-gloss black and surely not disputing since age can have an effect but seems more like a satin black on everything I've ever had the opportunity to review like this one below or one that William posted. I had put this info on my build thread as I ended up using the vacuum valve and master cylinder cover for our restoration.
https://www.camaros.net/threads/time-for-another-68-z-28-to-be-restored.182584/page-43#post-2537218

[Sauron327]

 Semi-gloss and satin terms used by many people vary unless they understand them. One person's satin is another's semi gloss, and vice versa. Gloss levels fall into ranges. And forget about relying on the screen for an accurate representation.

[DuWayne Ladner]

Alright, as this post is right up my alley, for the same reasons. The number 1 gripe in the whole of my restoration is of course the Master cyl, purchased 1 from a major Camaro Vendor, came to me in El naturale and now is the sore spot for me every time open the hood, for show at car shows, Dag gum it surface rust already. So I’m open to suggestions as to remedy this on the car. To dam old for removal and cleaning. Do got a question, can I use a rust prohibitive as a primer, then good semi black cover coat? Thanks, all here!

[DuWayne Ladner]

Here is a few photos of my Master cyl gripe. Installed during resto to present.

[Sauron327]

Alright, as this post is right up my alley, for the same reasons. The number 1 gripe in the whole of my restoration is of course the Master cyl, purchased 1 from a major Camaro Vendor, came to me in El naturale and now is the sore spot for me every time open the hood, for show at car shows, Dag gum it surface rust already. So I’m open to suggestions as to remedy this on the car. To dam old for removal and cleaning. Do got a question, can I use a rust prohibitive as a primer, then good semi black cover coat? Thanks, all here!

Clean the rust off, epoxy and topcoat it. I've done them neatly on the car. I stock auto paint, but you can use a quality primer and paint and it will be fine.

[DuWayne Ladner]

Thanks Sauron327!