Brake pedal Stiffness.
Thread Starter
Heel & Toe
Joined: Mar 2009
Posts: 19
Likes: 0
From: Limerick Ireland
Brake pedal Stiffness.
Hi Guys the brake pedal on my vette sometimes gets extremely stiff making braking a bit of an effort however on other occasions it seems to function fine. I have drained and replaced the brake fluid and was considering replacing the master cylinder. Is there anything else I should be looking at?
Tony
Tony
Thread Starter
Heel & Toe
Joined: Mar 2009
Posts: 19
Likes: 0
From: Limerick Ireland
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
How old are your flexible brake lines? Sometimes they fail in mysterious ways.
The should be replaced every 20 years or so.
Or you could have a piston that is sticking, you'd have to pull all the calipers off to see tho.
The should be replaced every 20 years or so.
Or you could have a piston that is sticking, you'd have to pull all the calipers off to see tho.
Intermediate
Joined: Mar 2009
Posts: 37
Likes: 0
stiff pedal
The brake booster was the likely culprit if it was a power brake car, but on a manual brake car, that's a very curious problem. Usually, the issue is with a pedal going softer. You're going to have to go through the system, 1 part at a time looking for the problem, starting with the master cylinder, and checking distribution blocks, metering valves, and everything else including the brake hoses and calipers.
Check the master cylinder first to be sure the piston is fully retracting and there is no blockage in the little bleed holes in the bottom of the fluid reservoirs. A stuck or malfunctioning valve in the metering block ( proportioning valve) could also be a culprit..and then keep looking down stream one part at a time.
Check the master cylinder first to be sure the piston is fully retracting and there is no blockage in the little bleed holes in the bottom of the fluid reservoirs. A stuck or malfunctioning valve in the metering block ( proportioning valve) could also be a culprit..and then keep looking down stream one part at a time.
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
The brake metering valve (proportioning valve ) will most probably not do anything to the brake pressure because it is only a differencial pressure sensor that actuates a switch bringing on the red warning light. It is not a proportioning valve as such and does not regulate any brake pressure nor flow. The brake pressure to the rfont is the same as to the back, only the brake pistons are different diameter front to back .This assures that the front brakes harder , only because of much bigger caliper piston diameter.
If there is nothing wrong with the master cylinder, I would guess that a flex hose is blocked.
Should be easy to see on a brake test bench. Take the car to the garage to test the brakes on the roll, they will tell you which side is at fault or even wich system, front or back.
Rgds. Günther
The brake metering valve (proportioning valve ) will most probably not do anything to the brake pressure because it is only a differencial pressure sensor that actuates a switch bringing on the red warning light. It is not a proportioning valve as such and does not regulate any brake pressure nor flow. The brake pressure to the rfont is the same as to the back, only the brake pistons are different diameter front to back .This assures that the front brakes harder , only because of much bigger caliper piston diameter.
If there is nothing wrong with the master cylinder, I would guess that a flex hose is blocked.
Should be easy to see on a brake test bench. Take the car to the garage to test the brakes on the roll, they will tell you which side is at fault or even wich system, front or back.
Rgds. Günther
