Weird Brake Problem
Thread Starter
Racer
Joined: Mar 2004
Posts: 305
Likes: 0
From: Houston Texas
Weird Brake Problem
This is a very unusual problem, but it has me stomped.
I have a 1985 Coupe.
It seems that my brake master cylinder was going out. The brake pedal would travel to the floor, with no braking power at all.
I tried bleeding the brake system, no pedal difference.
I even had my wife push down on the brake pedal, while I watched the fluid in the master cylinder. The fluid never moved.
My brake discs are in good shape.
A few days earlier, I did back the car several feet with the parking brake on. (Don't know if this makes a difference.)
I let the car set for a week. I replaced the fuel sending unit and fuel pump. When I finished, I started the car. I pushed on the brake pedal, (force of habit). The brake pedal is now hard, instead of going to the floor. I NOW have brakes.
Is my master cylinder on its way out?
I am afraid to drive it now, because until I know why the brakes acted the way they did, I can't be sure that they won't go out again.
This is my 1st vette. Is there something about vettes that would make this situation make sense???
I have a 1985 Coupe.
It seems that my brake master cylinder was going out. The brake pedal would travel to the floor, with no braking power at all.
I tried bleeding the brake system, no pedal difference.
I even had my wife push down on the brake pedal, while I watched the fluid in the master cylinder. The fluid never moved.
My brake discs are in good shape.
A few days earlier, I did back the car several feet with the parking brake on. (Don't know if this makes a difference.)
I let the car set for a week. I replaced the fuel sending unit and fuel pump. When I finished, I started the car. I pushed on the brake pedal, (force of habit). The brake pedal is now hard, instead of going to the floor. I NOW have brakes.
Is my master cylinder on its way out?
I am afraid to drive it now, because until I know why the brakes acted the way they did, I can't be sure that they won't go out again.
This is my 1st vette. Is there something about vettes that would make this situation make sense???
Melting Slicks
Joined: May 2003
Posts: 2,496
Likes: 1
From: alaska
hate those weird things when it comes to brakes.did you have to add any fluid when the pedal first went down?if so maybe you got some air.
for peace of mind maybe take it to a midas or similar for an inspect and bleed.
shouldnt cost to much and would ease the mind.
i bought a vacuum type bleeder a while back that works slick.it simply sucks the fluid through via each bleeder.(requires compressed air to run it-100 bucks at napa)
another nice way to go for bleeding are the speed bleeders that replace the bleed valves at each wheel cylinder.you just loosen them and pump the pedal.
for peace of mind maybe take it to a midas or similar for an inspect and bleed.
shouldnt cost to much and would ease the mind.
i bought a vacuum type bleeder a while back that works slick.it simply sucks the fluid through via each bleeder.(requires compressed air to run it-100 bucks at napa)
another nice way to go for bleeding are the speed bleeders that replace the bleed valves at each wheel cylinder.you just loosen them and pump the pedal.
Pro
Joined: May 2004
Posts: 712
Likes: 26
From: Santa Maria CA
I had a similar problem with an older Eldorado. Midas replaced the Master Cylinder, rebuilt the calipers, ect. problem still was not fixed.The brakes would work fine for a while, then when I least expected it the pedal went to the floor. A local independent brake shop finally found the problem after keeping the car for a few days. A vacuum hose had become soft with age causing it to occasionally collapse and cut off all vacuum to the brakes. After the hose was replaced, no more problems. Might be something for you to check.
Melting Slicks
Joined: Jul 2004
Posts: 2,018
Likes: 1
From: OR
It seems that my brake master cylinder was going out. The brake pedal would travel to the floor, with no braking power at all.
A bad master cylinder is all I know of that could cause the pedal to go to the floor. A brake booster problem would cause a hard pedal, but not a low one. An idiot light should have came on when this happened. Did it?
A bad master cylinder is all I know of that could cause the pedal to go to the floor. A brake booster problem would cause a hard pedal, but not a low one. An idiot light should have came on when this happened. Did it?
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
Master cylinders have check valves, rubber rings that keep the fluid going in the right direction. If there are no leaks, then the fluid is being pushed back into the reservoir. The check valves are not working properly. Best swap the MC out.... 
