My 69 convertible has the stock type front single caliper brakes and rear drums. When I restored the car I rebuilt the brakes, booster and added a new MC and new lines. My system has a proportioning valve bolted to the booster, brake switch/metering block and a valve under the drivers door on the subframe.

My question is....With a stock system how well should it perform? I bled the system really well and the pedal is firm, but if I mash the brake pedal the brakes will not lock up. The car seems to brake OK, but I guess I was wondering how well the stock setup SHOULD work(since I seem to have a knack for screwing thing up!) and if it is a problem that I can't lock up the brakes.

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<A HREF="http://www.stratagaz.com/69LM1/1969LM1Convertible.htm" TARGET=_blank>My 69 LM1 Convertible
</A>

The stock system will lock the front brakes pretty easily if all things are right.
Make sure air can get into the booster from under the dash.
There is foam baffeling that can rot and prevent good air flow into the booster.
Make sure your engine has 15 to 17 inches of vaccum and there is a good check valve on the booter to retain vaccum.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327 original owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer

[This message has been edited by davidpozzi (edited 02-13-2003).]

My engine make about 15 inches of vacuum at idle, so I guess that I have a problem! Great, I'm sure it was another one of my classic foul-ups!

I have no clue what this breather or foam is on the booster. I have another rebuilt booster in my garage, so I can look at it when I get home. I do remember a white piece of plastic on the back that the rod for the brake pedal goes through. I'm really not that great with brakes. I know how the front disc brake assembly bolts together(since I had to do that) and I know how the rear drums go together(I had to do that too), but I don't know how to check any of the clearances or measure what should move and how far. The extent of my brake experience is bolting it together and making sure that the wheel can turn(although the front discs do drag, but I think that's normal), hooking up the lines, MC and booster and bleeding the system.

I did reuse my proportioning valve, brakes switch/metering block and whatever the valve is for under the drivers door without rebuilding them(if that's even possible). Could they be causing a problem as everything else is new/rebuilt?

Also, my rear drum brakes don't have "self adjusters" is that a problem? I just have to manually check/set them once in a while.

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<A HREF="http://www.stratagaz.com/69LM1/1969LM1Convertible.htm" TARGET=_blank>My 69 LM1 Convertible
</A>

My stock front discs don't lock up either, although I am using a manual system. It has organic pads on there, which I am thinking about upgrading to semi-metallic if I can stop spending money on the engine.

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Matt Jones
1969 Base Camaro
Vortec 355, Perf. RPM, Demon Carb., TH-400
All sheetmetal is NOS GM
See my UPDATED webpage at: http://www.geocities.com/compuboy007/ (Updated: 1/13/03)

The pedal feels very stiff and I thought that with power brakes that the pedal would be a little softer and no matter how hard I press the pedal the brakes won't lock. Is 15" of vacuum at idle(in park not in gear) too low for the power brakes?

I'm going to check the vacuum line and maybe replace the residual valve(under the drivers door) in an effort to improve braking. I just don't have a good "feel" for what the best performance I can expect out the stock system is. I think the stock bore is 1 1/8 on power MCs, would it help anything to try and change to a different bore size?

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<A HREF="http://www.stratagaz.com/69LM1/1969LM1Convertible.htm" TARGET=_blank>My 69 LM1 Convertible
</A>

Yes, if you reduce the bore size, the brakes will have more power. One problem is that your brake pedal ratio with power brakes is about half what a manual system has, so no vaccum or low vaccum is a big concern.

If you try a 1" bore from a 70's vette, make sure the pushrod hole in the master cyl is the same as your current one.
There is a deep hole MC and a shallow hole MC.
The deep hole MC's are used on most manual systems to keep the pushrod from falling out.

Many first gen boosters use the deep hole MC too. Most second gen's have the shallow hole for power brakes and some of the manual systems I've seen on manual brake second gen's have a retainer cup over the rear of the MC to hold the pushrod in.

If you get the Performance friction pads, use the standard ones not the Z rated. They require more effort when cold.
I hear the standard PF pads require less effort than the origonal GM pads.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327 original owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer