Give me a BRAKE
Thread Starter
Instructor
Joined: Mar 2009
Posts: 187
Likes: 1
From: WA
Give me a BRAKE
I just replaced all of my calipers, rotors (crossdrilled), brakes, flexible brake lines (using Steel-braided now), and brake booster. I went from an extremely sponge like brake feel that would go all the way to the floor and hardly stop my vette to an extremely stiff brake pedal that stops better, but still not so great.
I'm confident my spongyness came from leaky calipers and I should expect some extra firmness going from rubber to steel-braided lines at the wheels, but it just does not feel right. The master-cyl is not very old which is why it wasn't replaced and I'm pretty good with brakes, so I doubt I did anything wrong at the wheels. The two things I've never dealt with is the booster and proportioning valve. I didn't touch the valve during the replacement process, so I'm thinking booster. It's new and when I take the vacuum line off of it, my engine nearly dies, so I know there is at least some vacuum.
Does anyone know other types of tests I can perform to get more pressure to the wheels? i.e. specific vacuum required for the booster?
I'm confident my spongyness came from leaky calipers and I should expect some extra firmness going from rubber to steel-braided lines at the wheels, but it just does not feel right. The master-cyl is not very old which is why it wasn't replaced and I'm pretty good with brakes, so I doubt I did anything wrong at the wheels. The two things I've never dealt with is the booster and proportioning valve. I didn't touch the valve during the replacement process, so I'm thinking booster. It's new and when I take the vacuum line off of it, my engine nearly dies, so I know there is at least some vacuum.
Does anyone know other types of tests I can perform to get more pressure to the wheels? i.e. specific vacuum required for the booster?
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
I just replaced all of my calipers, rotors (crossdrilled), brakes, flexible brake lines (using Steel-braided now), and brake booster. I went from an extremely sponge like brake feel that would go all the way to the floor and hardly stop my vette to an extremely stiff brake pedal that stops better, but still not so great.
I'm confident my spongyness came from leaky calipers and I should expect some extra firmness going from rubber to steel-braided lines at the wheels, but it just does not feel right. The master-cyl is not very old which is why it wasn't replaced and I'm pretty good with brakes, so I doubt I did anything wrong at the wheels. The two things I've never dealt with is the booster and proportioning valve. I didn't touch the valve during the replacement process, so I'm thinking booster. It's new and when I take the vacuum line off of it, my engine nearly dies, so I know there is at least some vacuum.
Does anyone know other types of tests I can perform to get more pressure to the wheels? i.e. specific vacuum required for the booster?
I'm confident my spongyness came from leaky calipers and I should expect some extra firmness going from rubber to steel-braided lines at the wheels, but it just does not feel right. The master-cyl is not very old which is why it wasn't replaced and I'm pretty good with brakes, so I doubt I did anything wrong at the wheels. The two things I've never dealt with is the booster and proportioning valve. I didn't touch the valve during the replacement process, so I'm thinking booster. It's new and when I take the vacuum line off of it, my engine nearly dies, so I know there is at least some vacuum.
Does anyone know other types of tests I can perform to get more pressure to the wheels? i.e. specific vacuum required for the booster?
I had to go around at least 3 times to get a good pedal
Jim
Thread Starter
Instructor
Joined: Mar 2009
Posts: 187
Likes: 1
From: WA
Regardless, I'll go around it a couple more times after checking for vacuum (thank you for that measurement). Shoot, I just thought of something...
My replacement calipers have "3" bleeders. While mounted on the car, 1 (inner I think) is at the top with 2 (inner and outer) at the bottom of the caliper. I believe I did inner and then outer. Is that right?
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
I went through the entire system once. My experience is that once you get a stiff pedal, it's redundant to keep going around. But then again, I've never dealt with a pedal that was too stiff. Can air cause a stiff pedal? I thought it compressed causing it to get 'squishy'.
Regardless, I'll go around it a couple more times after checking for vacuum (thank you for that measurement). Shoot, I just thought of something...
My replacement calipers have "3" bleeders. While mounted on the car, 1 (inner I think) is at the top with 2 (inner and outer) at the bottom of the caliper. I believe I did inner and then outer. Is that right?
Regardless, I'll go around it a couple more times after checking for vacuum (thank you for that measurement). Shoot, I just thought of something...
My replacement calipers have "3" bleeders. While mounted on the car, 1 (inner I think) is at the top with 2 (inner and outer) at the bottom of the caliper. I believe I did inner and then outer. Is that right?
Pedal is hard to push & take a lot of effort to stop? Make sure you have sufficient vacuum at the booster and no vacuum leaks. Check your vacuum readings while stepping on the pedal also & listen for a hissing noise under the dash indicating a vacuum leak. Lost a booster on my Mustang once while stopping at an intersecting. Car stalled, no brakes, went right through the stop sign.
Luckily no one was coming. Went right home & changed my shorts 
Le Mans Master
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