Date Code Decoding & Rebuilding A 1970 GS Drum Brake Master Cylinder

Interesting that there are no bleeder screws, my original CT master cylinder has bleeder screws. It is from a 68 though so they must have changed.

 

Mine is power drum. Wonder if they changed or if manual drum did not get bleeders?

 

I thought they had bleeders as well - Hmmm.

 

From my observations Buick power brake cars had master cylinders with bleeders. The non power brake cars did not have bleeders. The drum brake master cylinders all had the same "CT" code.

 

That would jive w/what we're seeing here, just surprising they'd have the same code. I sent Adam the M/C for Mike's Teal Mist (power drum) car & it had bleeders but I never checked the code - He'd just asked for one w/them & I had an orig booster/MC siting here.

Now I really have to look and see what M/C I have stashed away for my manual drum '70 350 4-sp. IIRC it came off a manual drum '70 Skylark 4-door which was why I grabbed it.

 

My 69 4 speed convertible has power drums with bleeders "CT" code.
Ryan's 70 show car had the original manual NO bleeder cylinder. CT code also.

 

Interesting. Still learning stuff on these cars. Goint to try & do a concours resto on one so surely will have plenty of questions for you, lol. You have a reputation. Did you get one of those NOS M/C rebuild kits from Gregg? He'd said one was for you.

 

Gregg came through with a kit for me.

 

I checked the M/C I have put away for my car - No bleeders but also too pitted to make out any code. I'll post a wanted ad but I'm looking for a nicer one if anyone has one.