Brake question

[DanEC]

Well - I may be completely off base but since I didn't find anything about your prior experience in older, manual brake cars, I wonder if it may be your expectation the ERA will brake like a new car. I have a 66 manual brake Vette and the old GM engineers have said several times over on Corvette Forums that the car has a high level of braking performance, even compared to newer cars, but they were designed in an era when higher pedal pressure was the norm for their engineering departments. In other words - you really have to really stomp on the brakes and when you do they will haul you down. That was how they were designed then. When I picked up my new GT350 Shelby, ever time I barely touched the brake pedal for about a month, it threw me against the seat belt until I got used to them. It's all a matter of pedal ratio, MC size, piston area and power/no power assist. Possibly Bob can weigh in the ERA design.


I may be off-base on this and maybe something is wrong. Sounds like you may need to step down slightly in size on the master cylinder piston diameter and live with a bit longer brake pedal stroke for a bit easier pedal pressure - and hopefully improved response.

[classical glass]

Originally Posted by DanEC

Well - I may be completely off base but since I didn't find anything about your prior experience in older, manual brake cars, I wonder if it may be your expectation the ERA will brake like a new car. I have a 66 manual brake Vette and the old GM engineers have said several times over on Corvette Forums that the car has a high level of braking performance, even compared to newer cars, but they were designed in an era when higher pedal pressure was the norm for their engineering departments. In other words - you really have to really stomp on the brakes and when you do they will haul you down. That was how they were designed then. When I picked up my new GT350 Shelby, ever time I barely touched the brake pedal for about a month, it threw me against the seat belt until I got used to them. It's all a matter of pedal ratio, MC size, piston area and power/no power assist. Possibly Bob can weigh in the ERA design.


I may be off-base on this and maybe something is wrong. Sounds like you may need to step down slightly in size on the master cylinder piston diameter and live with a bit longer brake pedal stroke for a bit easier pedal pressure - and hopefully improved response.

Hi, I run a corvette restoration shop specializing in 53-67 Corvettes. I have a good feel on what non power brakes are like. My Cobra is nothing like that. I have a 57, 58 fuel injected and a 67 427 430hp.I can lock up the brakes on all of them. That could not happen with the Cobra. I'm believing the problem lyes with the rotors. They feel too smooth and after 50 or so miles they should show some kind of skuff or circular wear pattern.I'm thinking the new shoes are not being broken in properly. I've done everything else that I could think of. One thing is for sure I will not drive this car until I get good brakes.
Thanks

[patrickt]

Originally Posted by classical glass

Hi, I run a corvette restoration shop specializing in 53-67 Corvettes. I have a good feel on what non power brakes are like. My Cobra is nothing like that. I have a 57, 58 fuel injected and a 67 427 430hp.I can lock up the brakes on all of them. That could not happen with the Cobra. I'm believing the problem lyes with the rotors. They feel too smooth and after 50 or so miles they should show some kind of skuff or circular wear pattern.I'm thinking the new shoes are not being broken in properly. I've done everything else that I could think of. One thing is for sure I will not drive this car until I get good brakes.
Thanks

You mentioned in Post #9 that your rotors do not look like mine. Why don't you just pull them off and have them turned and see if that makes a significant improvement? We know the big brake design works, so it's just a case of figuring out which component of yours is faulty -- and there's not that many pieces in the puzzle. Turning the rotors is a cheap and easy shot in the dark.

[DanEC]

Originally Posted by classical glass

Hi, I run a corvette restoration shop specializing in 53-67 Corvettes. I have a good feel on what non power brakes are like. My Cobra is nothing like that. I have a 57, 58 fuel injected and a 67 427 430hp.I can lock up the brakes on all of them. That could not happen with the Cobra. I'm believing the problem lyes with the rotors. They feel too smooth and after 50 or so miles they should show some kind of skuff or circular wear pattern.I'm thinking the new shoes are not being broken in properly. I've done everything else that I could think of. One thing is for sure I will not drive this car until I get good brakes.
Thanks

Yeah - I've owned 427 manual brake Corvettes for most of the last 39 years and done more brake work and caliper rebuilds/replacements on them than I can remember. They take a lot of pedal pressure but they will stop you.