'91 Brake Problems

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Mar 15, 2004 | 08:55 AM

dailo

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Racer

Joined: Dec 2003

Posts: 349

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From: Hong Kong

'91 Brake Problems

Hi

I have a 91 Vette out here in HK. As you may or may not know, its windy hill roads everywhere, going up and downhill constantly without fast highways. Sounds great huh.
Driving around all day long, the brake pedal travel increases as the brakes and engine gets hot. After driving for a while with the hot brakes, the pedal will travel all the way to the floor. I have replaced the master cylinder flushed the system, replaced the fluid numerous times. I would like to change the brake system to more or less cross drilled rotors to dissapate the heat, because by the time I stop the car to get out, the wheels are too hot to touch. Can someone recommend what to do about this?

Thank you

Mar 15, 2004 | 11:43 AM

edsalinas

Melting Slicks

Joined: May 2002

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From: Tucson Az

St. Jude Contributor

Re: '91 Brake Problems (dailo)

Hello HK, and welcome aboard........

You're booster may be going out, do you hear any "air" type noise when the pedal is to the floor? Also make sure all the vacuum lines are good.

:cheers:

Mar 15, 2004 | 09:02 PM

dailo

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Racer

Joined: Dec 2003

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From: Hong Kong

Re: '91 Brake Problems (edsalinas)

No air noises at all, just feels like theres nothing there to push, but if you pump the brakes about 3 times, it comes back.

Also, the pedal travel increases and decreases all the time

Mar 15, 2004 | 10:15 PM

ShawnZR-1

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From: Canton GA

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Re: '91 Brake Problems (dailo)

Sounds more like brake fade. What color is your brake fluid? First thing I would do is switch to a synthetic, check and replace your soft hoses at the calipers and certainly check for any leaks around the bleeder screws, caliper pistons and the master cylinder itself.

Mar 16, 2004 | 12:07 AM

Mrcorvette91

Pro

Joined: May 2000

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From: Etowah, Tennessee

Re: '91 Brake Problems (ShawnZR-1)

Just remember...the silicone (DOT 5) brake fluid is NOT compatible with DOT3 or 4. It WILL create sludge, and damage every brake component in the system if the complete system is not properly flushed out. Believe me, this comes from motorcycle experience..also, only DOT 3 or 4 is for anti-lock brakes..the DOT5 will NOT work properly. :flag :chevy

Mar 16, 2004 | 12:16 AM

h rocks

Safety Car

Joined: Apr 1999

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From: Ohio

Re: '91 Brake Problems (dailo)

Welcome dailo! If you are convinced that your mechanical components are good, then it comes down to either air getting into the system, or you never got it all out! What method are you using to bleed the brakes? Come back with more specifics about your processes, and there are enough resources here to help you fix your problem.
BTW, the "holy rotors" won't help a bit, except to expedite cracking and wear out your pads quicker. :cheers:

Mar 16, 2004 | 09:21 AM

dailo

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Racer

Joined: Dec 2003

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From: Hong Kong

Re: '91 Brake Problems (dailo)

Well basically, the bleeding is done at the Cadillac service centre in Hong Kong... So im sure they know what they are doing. Also, there is DOT 3 Fluid in there. Im sure that the brakes on the car are designed for highway driving and not these conditions, which I guess you could consider similar to racing. The Fluid is still the colour of Olive Oil, and all the air has been taken out... its just when the engine is cold, or the car is cold, there is a difference in pedal travel than when its hot. Dont know if that helps... but thanks for trying anyway.