'70 GSX Master Cylinder Color

So for 70 you either have EA or CT and that’s all she wrote.

 

Installed and brakes bled today.

 

Thank you for using an original brake booster. Very rare. Outstanding.

 

It was on the car from new and works really well. Thank you.

 

If you want to be super correct put a light blue paint dot on top of the booster. All originals I have see n one. This is my GSX

 

Thanks to all for the information, advice and pictures.

As far as the MC goes, I am fortunate to have the correct one. I will Calyx it and the hold-off valve for correct looking castings.

Art B

 

"So for 70 you either have EA or CT and that’s all she wrote."
Are you sure about that Dave?

In another thread they are discussing if the Manual Drum Master Cylinder was a different casting then the one they used for the Power Drum cars.
I always thought they were the same too, but they think the non-power MC was a different casting and did not have the provision for bleeders.

Do you think 2 different cast pieces would have the same stamped code? Which is correct?

You can't always use Service Manuals, as they only reflect what was done at the time of printing and will not reflect changes that went on during production. Plus, almost always they show info from the very beginning of the model year. This is why I use the Assembly manuals and check the revision dates so well, and even then I get caught.


Now setting aside the "stamping info" as described above, I found some interesting things about the 70 Tags that were used to "ID" the sub assemblies. When I get that written up I will post it here.
Duane

 

Here's what I know about masters. I know Olds used an EA in 1969 on PDB's, because There's one on my 442. I know GTO's used the EA, because I've owned GTO's in the past, but I'm not sure when they stopped. As far as a different master for Buick manual vs power drum, I know the bleeders were put on the masters because of the angle of the cylinder. I think those master bleeders were the last to be bled, and somehow the ones at an angle needed to be bled. A non-power manual master was like horizontal off the firewall, and a power drum master would be at an an angle. That's what I had either read, heard, or was told many years ago. So I would tend to agree with Duane there may be a difference there.

 

My opinion is that I know the 309 master was used on GTO's in 1969 . The 309 was also used on Chevelles in 1969 but was a BA code., The only make I know used the 309 in an A body on a 1970 was Buick. The other A bodies switched to the single bail square body in 1970. The info people need to correctly restore cars is mind boggling ..

 

No idea if it’s correct but that is what Buick is telling us.

 

I have found plenty of mistakes in service manuals so anything is possible.

 

The info people need to correctly restore cars is mind boggling ..

Yes it is, and it's getting harder and harder to restore these correctly as people dig deeper into them.

However, the idea of Judging these cars at the BCA/GSCA/BPG etc. events was not to dig into everything to the point where we had to spend a couple of hundred thousand dollars to restore a car to get an award.

We have gone out of our way to NOT bring the restorations of these cars to the level that they are building some Corvettes and Camaro's. I remember 1 guy getting points knocked off on his 67 Vette for having the wrong screws, even though it was an original car that was never taken apart. How do you explain that?
Duane

 

They were out of screws on the assembly line and used next closest thing they had. No accounting for that. Usually cars I have ripped the headliners out of had black flathead screws that look like lower windshield trim screws only were black and were on attaching parts. When I ripped the original headliner out of my GSX it had the same screws in chrome. So it’s what they had.

 

Agreed,
But the bottom line is we never wanted to force our people to build cars to that level..........and even then we ended up being more "picky" then the AACA, which supposedly gives cars their "Pedigree"
Duane

 

I lost out having a perfect score at the GS Nationals on my GSX at the GS Nationals for having the correct chrome screws on my windshield stainless trim??? Judge(not Duane)thought they were a different type zinc? It was the second time I took it there. You were judge the first time but not the second. I even painted my front sway bar brackets black that you got me on the first time. Mine were zinc but that is story for another day. Anyway still stumped on those screws?? I know they are correct. Have taken off many originals.

 

. But in the other side of your comment is if I bring a car to a National level event I would like to see two things . One is a great bunch of cars in any Class Two is I would like to see a KNOWLEDGABLE judge look at my car and give me some items needed to make it better. There is no win in a poorly judged car show for anyone.

 

There are plenty of knowledgeable judges that have done cars at the Nationals including the guy that judged mine. Bottom line is no one knows 100 percent of the car but if you do your own research and know you are correct it sticks in your craw. Being a judge is also a thankless job. I have seen some nasty arguments.

 

Damn Air Conditioned Cars.