Settle a brake argument

[Bonnewagon]

Many moons ago I scored a set of first gen Firebird front disc brakes. The guy wanted 4 wheel drums because he liked a "high pedal" which you can get with manual drums. But then I was stuck with the increased pedal travel of the boosted discs. Luckily the '68 used an adjustable pedal push rod. I was able to modify it to work with the booster and get a fairly high pedal. I am often tempted to fabricate something like that for my car but I worry about things like metal strength and weld decay. Brakes are not something to take chances with.

 

[fleming442]

Many moons ago I scored a set of first gen Firebird front disc brakes. The guy wanted 4 wheel drums because he liked a "high pedal" which you can get with manual drums. But then I was stuck with the increased pedal travel of the boosted discs. Luckily the '68 used an adjustable pedal push rod. I was able to modify it to work with the booster and get a fairly high pedal. I am often tempted to fabricate something like that for my car but I worry about things like metal strength and weld decay. Brakes are not something to take chances with.

That's when you have heft up your cajones and SEND IT!

 

[pontiacgp]

Many moons ago I scored a set of first gen Firebird front disc brakes. The guy wanted 4 wheel drums because he liked a "high pedal" which you can get with manual drums. But then I was stuck with the increased pedal travel of the boosted discs. Luckily the '68 used an adjustable pedal push rod. I was able to modify it to work with the booster and get a fairly high pedal. I am often tempted to fabricate something like that for my car but I worry about things like metal strength and weld decay. Brakes are not something to take chances with.

If you find the pads backing off too much and giving you a low pedal you can add an inline residual valve We used a 4 lbs residual valve on the disk brakes and a 10 lbs for the drum on circle track cars. They also have 2 lbs valve but we found that allows the pads to back off too much.

 

[69hurstolds]

Many moons ago I scored a set of first gen Firebird front disc brakes. The guy wanted 4 wheel drums because he liked a "high pedal" which you can get with manual drums. But then I was stuck with the increased pedal travel of the boosted discs. Luckily the '68 used an adjustable pedal push rod. I was able to modify it to work with the booster and get a fairly high pedal. I am often tempted to fabricate something like that for my car but I worry about things like metal strength and weld decay. Brakes are not something to take chances with.

Many of the booster rods that attach to the brake pedal has some adjustment to it. There is a screw on adapter to fit the pin on the brake pedal and should be a lock nut right underneath. Not MUCH adjustment, but some.

 

[64nailhead]

Ever see a commercial toilet stuck in flush mode? Same principle.

Why does the conversation always have to go into the toilet?


Kidding aside, I'm not familiar with any G-body that wa offered with manual brakes, but perhaps they were. On other models that I'm familiar with though, the master cylinder and brake pedal are not the same between manual and power, or location where the master cylinder rod attaches to the brake location is in a different spot.

On terms of pedal travel where different components are used for power vs manual, I've always been under the assumption and seen that the travel was virtually the same.

 

[Wagonman100]

You might see the pedal drop when starting the car and getting vacuum into the booster, especially if you pumped the pedal after then engine was shut off the last time you drove the car, but that does not really translate into total pedal travel. You still have to push the pedal down the same amount to move the same amount of fluid to your brake components (the pistons for disc and the rods in the cylinders for drums) to actually stop the car. Before I started my Fauxmad project and took the wagon off the road, I drove it daily. Since I knew I was taking it off the road, I let some things go unrepaired when they broke. One of those things was the brake booster. I drove the car for about two months with no power brakes. I can tell you that you had to push the pedal down just as far to stop the car and the pedal was not appreciably any higher than when the booster was working. I just had to push harder to stop the vehicle. I never looked to see if there was another hole in the brake pedal arm to get more leverage because I could stop just fine. But I can tell you that actually stopping the vehicle while driving it with no boost assist compared to pushing on the pedal in your driveway with no boost assist are two different things. You just feel like the pedal is traveling further with the boost assist because it is easier to push the pedal down all the way.

 

[69hurstolds]

Kidding aside, I'm not familiar with any G-body that wa offered with manual brakes, but perhaps they were.

Just looking at the firewall shows you G-bodies weren't designed to come with manual brakes from the factory. The mounting seat is slanted which points everything up in the air. The hole is huge and there does not appear that there were any dimples to directly bolt an M/C to the firewall. 4 holes for the booster is all that's surrounding the main booster hole. The older A-body cars used a straight firewall with the angle for the power booster built onto the booster bracket. So if you have manual brakes, the M/C was level. Slightly tilted if power brakes. In fact, the adapters the aftermarket sells points downwards so the manual M/C is more level.

AFAIK, there's only one pin on the brake pedals, regardless of manual or automatic. This tells me there's no other type of M/C available for G-body.

One more check is on the parts book. No m/c I could find did not come without the angled reservoir, meaning it was always going to be at an angle. There was basically ONE power booster for every application of G-body that didn't come with a turbocharger (hydroboost). And I found no "adapter plate" or anything of that nature in the parts books to adapt an M/C directly to the firewall.

Conclusion- NO physical evidence exists that any G-body came with manual brakes from the factory. Not saying it's absolute, but it leaves a very high bar to prove otherwise. Many of the engines sucked hard back then, so there should have been plenty of vacuum!

 

[pagrunt]

Just looking at the firewall shows you G-bodies weren't designed to come with manual brakes from the factory. The mounting seat is slanted which points everything up in the air. The hole is huge and there does not appear that there were any dimples to directly bolt an M/C to the firewall. 4 holes for the booster is all that's surrounding the main booster hole. The older A-body cars used a straight firewall with the angle for the power booster built onto the booster bracket. So if you have manual brakes, the M/C was level. Slightly tilted if power brakes. In fact, the adapters the aftermarket sells points downwards so the manual M/C is more level.

AFAIK, there's only one pin on the brake pedals, regardless of manual or automatic. This tells me there's no other type of M/C available for G-body.

One more check is on the parts book. No m/c I could find did not come without the angled reservoir, meaning it was always going to be at an angle. There was basically ONE power booster for every application of G-body that didn't come with a turbocharger (hydroboost). And I found no "adapter plate" or anything of that nature in the parts books to adapt an M/C directly to the firewall.

Conclusion- NO physical evidence exists that any G-body came with manual brakes from the factory. Not saying it's absolute, but it leaves a very high bar to prove otherwise. Many of the engines sucked hard back then, so there should have been plenty of vacuum!

Malibu's & El Camino's did come with out power brakes as the base-base cars. Years back we converted a non power to power so a buddy's wife could drive the '78 Malibu he picked up, it even had a brake pedal for a stick car.

 

[69hurstolds]

Malibu's & El Camino's did come with out power brakes as the base-base cars. Years back we converted a non power to power so a buddy's wife could drive the '78 Malibu he picked up, it even had a brake pedal for a stick car.

I wanna see where this is. The parts book shows M/T brake pedals, but they're for power brakes. Now, I can find manual brakes for 77 on back. But nothing for 78-up. Again, there's no adapter listed anywhere I can find.

I reiterate I'm not saying they never made any with manual brakes, I'm just trying to verify which cars actually came with manual brakes and more importantly, how did they do it? Like what parts or did they have a different firewall, etc., etc.

 

[pontiacgp]