Topic: Brake problem
in Forum: C3 Engines, Driveline and Handling
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
I am having a brake problem and have taken it in to mechanic a couple of times but still the problem remains. After driving for 250-300 miles the brakes become sluggish, slow response time. I had to hit the brakes hard coming back from Santa Cruz, Ca. and now the brake light remains on, has happened before. As we are leaving for Florida in two weeks (in the Corvette, of course) I really need some help with this. Any suggestions???????????? It seems to me that brakes heat up and just don't work right. Not sure but seems that is what is happening
SPONSOR AD:: (Our Sponsors help support C3VR)
2 questions:
1: have you changed the fluid, rubber lines to calipers or calipers?
2: are there any visible signs of trace leakage around the ends of the calipers where the two sides connect?
I had that problem and it turned out to be the left rear caliper drawing air back into the system. I would completely lose brakes over time and have to re-bleed. I solved it by replacing the calipers, changing to braded steel lines, and replacing the master cylinder/changing the fluid.
It took all of these to eventually eliminate the problem of soft brakes completely.
Have replaced the master cylinder, completely drain and replaced brake fluid, replaced the rotars on the front, back rotors were fine. Brake pads been inspected and said they couldn't find anything wrong. Will try that with the calipers. Thanks alot. Bo
Try replacing the rubber brake hoses,they may look good on the outside ,but they turn into mush on the inside,sometimes the fluid wont back flow or just get trapped in the hose
C3VR Lifetime Member #93
If they didn't do it already, have them check the runout on all 4 rotors.
The specs allow .005" TIR, but if you have more than .003" the brake pistons will pump air into the lines.
Have him bleed the lines again, starting with rear pass. side, then rear drive side then front pass side and finally front drive side.
Also have the proportional valve checked to see if it is sticking.
Save the Wave!
Support the National Corvette Museum
Support the National Corvette Museum
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20225
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Bo, is your pedal going down too far, or, farther than "normal" when this happens?
If you had to "hit the brakes hard", and the light came on, that's telling you the proportioning valve has tripped, and there is a problem on one end or the other. You either have air in the system, or...when you got on the binders hard, the hoses swelled enough to trip the p-valve.
With the car running, you should be able to pop the pedal hard & quick, and the p-valve should reset, unless there is still air in the system, or the master is leaking internally.
If you had to "hit the brakes hard", and the light came on, that's telling you the proportioning valve has tripped, and there is a problem on one end or the other. You either have air in the system, or...when you got on the binders hard, the hoses swelled enough to trip the p-valve.
With the car running, you should be able to pop the pedal hard & quick, and the p-valve should reset, unless there is still air in the system, or the master is leaking internally.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
I installed a set of extreme brake calipers with stainless linings and new master cylinder with silicone fluid and for years now I've never had those problems again
Stainless braided lines are the way to go. You will feel the difference in pedal firmness. The rubber lines will expand ever so slightly and therefore reduce the pressure to the calipers. I did mine and will never put rubber on anything. Unless you want NCRS compliance do yourself a favor. A few bucks more but well worth it.
I also have a brake problem and have done the following: Bought new master cylinder, s/s calipers, pads, rubber hoses, power booster and bled the system 3-4 times with no air coming out. I am getting a good flow when bleeding but still have little peddle and stopping power is very weak. If I didn't bleed the master cylinder enough would I still have a good flow?
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20225
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Vette calipers can be a pain to fully bleed, due to the two sided design, and the dual bleeders on them in the rear. A pressure bleeder works best, but I know not everyone has one. Sometimes, a rubber mallet tapping on the caliper while bleeding will help dislodge air bubbles. It's best to fill the calipers with fluid before installing them, also.
Always start by bleeding the master cyl first. Most parts houses sell a kit("Help") with plastic fittings, and hose for doing this, if your master did not come with them.
Bleed 'em to death!
Always start by bleeding the master cyl first. Most parts houses sell a kit("Help") with plastic fittings, and hose for doing this, if your master did not come with them.
Bleed 'em to death!
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
in Forum: C3 Engines, Driveline and Handling
SPONSOR AD: (Our Sponsors help support C3VR)