Brake Bleeding- Pedal Feel
Thread Starter
Advanced
Joined: May 2006
Posts: 94
Likes: 36
From: Colorado
Brake Bleeding- Pedal Feel
Replaced the brake rotors, pads, brake hoses (with SS) and flushed, bled brakes. Emptied out the old fluid from the reservoir with a turkey baster. Never let any air inter the system by keeping a small amount in the bottom of the reservoir. I used a power bleeder and flushed system and cleaned out the reservoir with denatured alcohol. Then bled the system two times with fresh brake fluid. Pumped brakes with engine off 20 times and with engine running another 20 times. Bled system a third time. Ran almost two quarts of fresh brake fluid through the system. I'm sure I have no air or residue alcohol in the system. I did not cycle the abs system. I have no leaks. The pedal is tight and very solid no matter how hard I press it unless the engine is running, then the pedal can be pressed to the floor with moderate to hard pressure. Should the pedal have that much play with the engine running or do I have a problem? I don't recall the pedal feeling like this since I put the car up for the winter last September.
Intermediate
Joined: Oct 2001
Posts: 40
Likes: 2
From: santa clara ca
Brake Booster.
Disconnect and plug the vacuum line and see if the pedal still feels bad.
If it does, your brake booster has a leak, or if you are lucky, the vacuum plumbing associated with it is leaky.
You can also use one of those manual vacuum pumps to check the booster
Disconnect and plug the vacuum line and see if the pedal still feels bad.
If it does, your brake booster has a leak, or if you are lucky, the vacuum plumbing associated with it is leaky.
You can also use one of those manual vacuum pumps to check the booster
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
Did you go for a drive around the block? If after a short drive it still sucks you somehow got air into the system. I wouldn't have bothered with the denatured alcohol myself unless your fluid was black as night. I just did my Z and used a power bleeder, what did you use to bleed? I didn't cycle my ABS either.
Pro
Joined: Jan 2015
Posts: 607
Likes: 141
In my experience, and I’ve done full brake jobs (calipers, lines, pads) three times now on my ‘99 C5 and now my ‘04 C5.... unfortunately the only way you’re going to have the best “new” firm like pedal feel is using a Tech 2 and following the brake bleed procedure. You have to cycle the ABS. Never going to get fluid out of the ABS with using the brake pedal pump brake bleed or with just a power bleeder.
Last edited by C6Z_LS7; May 26, 2020 at 11:24 PM.
Thread Starter
Advanced
Joined: May 2006
Posts: 94
Likes: 36
From: Colorado
Did you go for a drive around the block? If after a short drive it still sucks you somehow got air into the system. I wouldn't have bothered with the denatured alcohol myself unless your fluid was black as night. I just did my Z and used a power bleeder, what did you use to bleed? I didn't cycle my ABS either.
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
I reread, he used a power bleeder. OP will the car lock the brakes? That'll cycle the ABS, but I can't say how much of that it takes to get the pedal right. I have never changed a caliper or line, just pads, rotors, and bleeds.
Thread Starter
Advanced
Joined: May 2006
Posts: 94
Likes: 36
From: Colorado
I did a quick test today for brake booster and checked the vacuum line. No leaks in the line and great vacuum present. With the vacuum line off and car running I have a good firm pedal. I'm leaning towards a bad booster or valve (if there is one.) I don't see how air could get into the the abs and be causing this. Is it not isolated from the brake system until activated? If it was the abs, wouldn't I have a soft pedal regardless? Please educate me.
I could have a bad master cylinder .
I could have a bad master cylinder .
Last edited by ClassicAuto; May 28, 2020 at 01:45 PM. Reason: another thought
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski