Hard Brake Pedal
Thread Starter
6th Gear
Joined: May 2013
Posts: 6
Likes: 0
From: naples fl
Hard Brake Pedal
Hi Everyone! I have a '90 conv. Just got it a month ago. Has some issues but I'm going through them now. runs and stopped great. I pulled it in the shop and did two repairs. when I finished I had no power to the brakes. Symtoms of a booster problem. The two things I worked on were taking out the Bose Gold CDM box and all 4 spkrs. the other was working on the dr, seat sport seat lumbar sys and seatback recliner. Took the parking brake lever off to clean it up. Then re-installed it. The Cdm box was a real pain. Did find that I didn't re-hook up the vac tube to the vent on the far right side. did hook it back up but didn't make a difference. Have checked vac to booster and it's strong. Driving me nuts! Love driving this car! To nice out to watch it sit in my shop! Any help would be very much appreciated!!!
Heel & Toe
Joined: Feb 2012
Posts: 21
Likes: 0
From: Queen Creek Arizona
with car running, radio off and you apply the brake pedal... do you hear a hissing sound?
If you do, power booster leaking (housing, diaphragm, inlet valve...)
The best advice I've had here is buying the FSM, troubleshooting guides for brakes (and all systems). I had the same issue on my '94, replaced the booster (and fluid reservoir).
Be sure to bleed the master cylinder brake reservoir before connecting the brake lines,
loosely connect brake lines and bleed again. If you don't introduce air into brake lines, you won't have to bleed the whole system.
If you do, power booster leaking (housing, diaphragm, inlet valve...)
The best advice I've had here is buying the FSM, troubleshooting guides for brakes (and all systems). I had the same issue on my '94, replaced the booster (and fluid reservoir).
Be sure to bleed the master cylinder brake reservoir before connecting the brake lines,
loosely connect brake lines and bleed again. If you don't introduce air into brake lines, you won't have to bleed the whole system.
Thread Starter
6th Gear
Joined: May 2013
Posts: 6
Likes: 0
From: naples fl
Hard Brake Pedal
Hi ddan! Been working on muscle cars for years. Went through all the checks and they seem fine. First newer corvette I've owned and thought it was something I might have done while working on the other things. Had an issue with the parking brake. Didn't realize the handle laid back down after engaged. Went down the road a couple blocks, felt the brake on, turned around and came back. At that point the power brakes still worked. Found my stupid little mistake! Then I worked on taking out the CDM under the pass side dash. The a/c canister vac line was off. I put it back on. It is very small and don't really think it would affect the booster. Couldn't see any other connectors other than the box that were unplugged.
Pro
Joined: May 2012
Posts: 519
Likes: 5
with car running, radio off and you apply the brake pedal... do you hear a hissing sound?
If you do, power booster leaking (housing, diaphragm, inlet valve...)
The best advice I've had here is buying the FSM, troubleshooting guides for brakes (and all systems). I had the same issue on my '94, replaced the booster (and fluid reservoir).
Be sure to bleed the master cylinder brake reservoir before connecting the brake lines,
loosely connect brake lines and bleed again. If you don't introduce air into brake lines, you won't have to bleed the whole system.
If you do, power booster leaking (housing, diaphragm, inlet valve...)
The best advice I've had here is buying the FSM, troubleshooting guides for brakes (and all systems). I had the same issue on my '94, replaced the booster (and fluid reservoir).
Be sure to bleed the master cylinder brake reservoir before connecting the brake lines,
loosely connect brake lines and bleed again. If you don't introduce air into brake lines, you won't have to bleed the whole system.
The first thing I had to do to my 86, besides tires was get a power steering booster.
Instructor
Joined: Feb 2013
Posts: 193
Likes: 18
From: Evansville IN
I also have a 90 model. Brake pedal is hard until I start the car. Flushed all new fluid thru the calipers, replaced the rubber hoses. I went thru a qt and a half of brake fluid bleeding the brakes, (in correct order). Pedal feels pretty good. Pumping them doesn't make them feel any better. They seem to stop me good, but it seems I have to push on the pedal too hard.
Thread Starter
6th Gear
Joined: May 2013
Posts: 6
Likes: 0
From: naples fl
Thanks Buddy!!!
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