69 4 drum power booster tag and 2gv carb spring

[KevinW]

Hey all, just some random questions for an early build 69.  I am pretty sure the little paper tag on booster check valve is CB for power disc, but what tag would have been used for 4 drum power brakes?

Also, what specs/color was the throttle return spring for a 2-bbl? Anyone with a pic? Thanks!

[KurtS]

It's CU for power discs, CG for power drums.

[KevinW]

thanks Kurt!

[KevinW]

Ok, here is my 1st attempt at the paper booster tag. font is pretty close IMO. I kinda guessed at the size (7/8"x 1 1/4") seem right to me. 

I hope to dial in my 2GV spring options and post another pic as soon as I locate a spare coil bracket :sigh:

Here is a pic of the check valve tag I made.  How close did I get it?

[KevinW]

Kurt, btw, my car came with 4 drum non-power of course.  I added the power MC/booster for safety. Still does not stop as well as discs.  Oh well.

[KevinW]

OK, for the carb springs, I have two candidates (after I found my bracket).

I skinny one and larger one.  Which is more correct? Thx

[rich69rs]

I added the power MC/booster for safety. Still does not stop as well as discs.  Oh well.

The drums new are 9.5” inside diameter with a discard diameter of 9.560”.  (Some sources say 9.590”.)

For the drums to work effectively and as designed it is absolutely necessary that you:

•  don’t exceed the 9.560” allowable inside diameter (so that the shoes don’t have to move excessively

•  on the front brakes - install the larger (longer and somewhat wider) shoe to the rear and the smaller shoe to the front

• ensure that you have the correct residual pressure valves in the master cylinder outlet ports.

Richard

[rich69rs]

I have two candidates (after I found my bracket).

I skinny one and larger one.  Which is more correct? Thx

My ride has the base 327/210 hp engine which has the small (1-1/4”) bore Rochester 2GV 2 Bbl.  The return spring on mine is more like the “skinny” one you show.

Richard

[KevinW]

Thanks Richard!  Skinny spring is what I will use!

On the brakes, I pull off the drums every spring to give them a clean and adjust.  I will look into what you posted. thx

[David K]

For the drums to work effectively and as designed it is absolutely necessary that you:
Upgrade to front disc.

[KevinW]

Funny!  I have thought about it, but with my Drum only rims, I would have to swap those out too. Unless I got the Right stuff 14" drum to disc kit.  Money, Money, Money

[GMAD_Van Nuys]

I don't see a problem using drum brakes on your Camaro as properly maintained, they are okay for normal street driving. 

[KevinW]

Thx!  Yes, I inspect/clean/adjust them every spring.  And plan my stops.  Twice I had panic stops and the brakes lockup and fade quickly!  but I stay as alert as possible!

Another 2GV mystery: I have two 2GV carbs.  Exactly the same except the vent cover is slightly different.  One has a full cover, the other a cover with a cutout.  I looked at the CRG report  http://www.camaros.org/carb.shtml and the pics of 68 and 69 had the cutout, but the 67 was not in frame. ps, I have only one carb tag 7029110 CH from 68, but not sure which carb it came off of.

[GMAD_Van Nuys]

Check out Richard Petty winning at Riverside in 1969.  They were still using drum brakes.

https://www.google.com/search?q=nascar+1969+riverside+raceway&sca_esv=c31d1b2737bb79d7&source=hp&ei=XhrXZ6y4DMbHkPIPnqqz0QM&iflsig=ACkRmUkAAAAAZ9cobtWpl42JEVqN5AR_dY-j3CGOy3sT&oq=nascar+1969+river&gs_lp=Egdnd3Mtd2l6IhFuYXNjYXIgMTk2OSByaXZlcioCCAEyBRAhGKABMgUQIRigATIFECEYoAEyBRAhGKABMgUQIRigATIFECEYnwUyBRAhGJ8FMgUQIRifBTIFECEYnwUyBRAhGJ8FSPJjUABYqUZwAHgAkAEAmAGZAaAB7wqqAQQxNC4zuAEByAEA-AEBmAIRoAKjDMICCxAuGIAEGLEDGIMBwgILEAAYgAQYsQMYgwHCAgUQABiABMICERAuGIAEGLEDGNEDGIMBGMcBwgIIEC4YgAQYsQPCAggQLhiABBjUAsICERAuGIAEGLEDGIMBGNQCGIoFwgIOEC4YgAQYsQMY0QMYxwHCAg4QLhiABBixAxiDARiKBcICCBAAGIAEGLEDwgIOEAAYgAQYsQMYgwEYigXCAgQQABgDwgIFEC4YgATCAggQABgWGAoYHsICBhAAGBYYHsICCxAAGIAEGIYDGIoFwgIIEAAYgAQYogTCAgUQABjvBZgDAJIHBDEzLjSgB6CiAQ&sclient=gws-wiz#fpstate=ive&vld=cid:8a5147d4,vid:_DmuONVqSq4,st:0

[KevinW]

• ensure that you have the correct residual pressure valves in the master cylinder outlet ports.

Richard

Richard, so what does a factory residual pressure valve look like?  I pulled the brass seat out of an old drum master cyl (rear port) and there was nothing there!  Now I am confused.