Major brake problem. Hard pedal and wont stop well.
12-26-2008, 09:25 AM
#1
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Thread Starter
Join Date: Aug 2005
Location: Kantuckee Yo'
Posts: 4,405
Major brake problem. Hard pedal and wont stop well.
First the specs.
1995 Camaro with full LS1 brakes from 2000ss minus the master cylinder.
Hawk HPS pads with 50% wear but look good.
Cross drilled slotted rotors with 90% smoothness.
Vaccum canister due to cam (which was not really needed anyway).
Just got finished refinishing the calipers and the brakes feel terrible. It takes a lot of pedal pressure to stop the car IMHO. Absolutely nothing responsive about these brakes period. The caliper pistons look great an slide in their bores with no binding. The seals look good and the sliders are buttery smooth. I do have cracks around the rotor drilled holes but that should not be the problem.
My 2007 Silverado and my wifes Accord have mega responsive brakes which dont require much pressure to stop. I assume the Camaro should be similar or at least more closer than this. There is clearly a problem.
I have bled out the ABS unit and all the lines several times so there should not be any bubbles. I do NOT have an ABS INOP light lit up on the dash so the PCM must think the system is fine. The pedal does not feel super soft, just mushy. The pedal feels rather normal when the car is turned off too.
I checked the booster by pulling the fitting out of the housing when the motor was off, it is holding vaccum. I assume its fine.
Could it be the Master cylinder? What are the signs of one going bad?
1995 Camaro with full LS1 brakes from 2000ss minus the master cylinder.
Hawk HPS pads with 50% wear but look good.
Cross drilled slotted rotors with 90% smoothness.
Vaccum canister due to cam (which was not really needed anyway).
Just got finished refinishing the calipers and the brakes feel terrible. It takes a lot of pedal pressure to stop the car IMHO. Absolutely nothing responsive about these brakes period. The caliper pistons look great an slide in their bores with no binding. The seals look good and the sliders are buttery smooth. I do have cracks around the rotor drilled holes but that should not be the problem.
My 2007 Silverado and my wifes Accord have mega responsive brakes which dont require much pressure to stop. I assume the Camaro should be similar or at least more closer than this. There is clearly a problem.
I have bled out the ABS unit and all the lines several times so there should not be any bubbles. I do NOT have an ABS INOP light lit up on the dash so the PCM must think the system is fine. The pedal does not feel super soft, just mushy. The pedal feels rather normal when the car is turned off too.
I checked the booster by pulling the fitting out of the housing when the motor was off, it is holding vaccum. I assume its fine.
Could it be the Master cylinder? What are the signs of one going bad?
12-27-2008, 10:01 AM
#2
Registered User
Join Date: Jul 2004
Location: MI
Posts: 1,174
How much manifold Vac @ idle? @ low speed cruz?
You need about 16" Hg Vac for the brake booster to apply sufficient force to the master cyl. Any less and the brakes have no vac assist.
I had 3" Hg @ idle and 13" @ cruz. Not enough with my app... (97ss 383 D1 M6).
Installed an electric vac pump from SSBC from Summit. Solved my problem. B.
You need about 16" Hg Vac for the brake booster to apply sufficient force to the master cyl. Any less and the brakes have no vac assist.
I had 3" Hg @ idle and 13" @ cruz. Not enough with my app... (97ss 383 D1 M6).
Installed an electric vac pump from SSBC from Summit. Solved my problem. B.
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