Dash brake light stays on.
Thread Starter
2nd Gear
Joined: Sep 2019
Posts: 2
Likes: 0
Dash brake light stays on.
Hello everyone. My name is Bill and I’m new to this forum.
I own a 1978 Vette that I’m actually selling to regain garage space.
I’d like to remedy the dash brake light situation before the new owner picks it up. He says it’s no big deal but I’d like it fixed. I thought it may have been the emergency switch but I checked it and it is fine.
The brakes work good and the master cylinder fluid level is fine.
I was considering the two brakes switches at the pedal but all the rear brake lights are in good working order. I’m perplexed and wondering if anyone else has had this same issue and knows the remedy.
Thank you.
I own a 1978 Vette that I’m actually selling to regain garage space.
I’d like to remedy the dash brake light situation before the new owner picks it up. He says it’s no big deal but I’d like it fixed. I thought it may have been the emergency switch but I checked it and it is fine.
The brakes work good and the master cylinder fluid level is fine.
I was considering the two brakes switches at the pedal but all the rear brake lights are in good working order. I’m perplexed and wondering if anyone else has had this same issue and knows the remedy.
Thank you.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
The dash brake light comes on when
1- The parking brake handle is moved up, to let you know the parking brakes are engaged ( unlikely if they are original)
2- There is a pressure differential in the brake system from a leak. Many think the switch plumbed in line with the Master Cylinder is a proportioning valve, it is not. It simply has a spool in it. Your brake system is divided between the front and back brakes. If a leak started in one or the other the pressure changes and the spool shifts making a switch to light the dash light.
You can check to see if the switch for the PB handle is still good and not stuck closed, if good check the M/C to see if one chamber is lower or empty. Look around the calipers for fluid. If that is the case you need a good brake job with new calipers or rebuilding yours if SS lined, new hoses if over 8 years old and don't forget the copper washers for the front hose to caliper connection. If the brakes are hard and even, no fluid seen your brakes should be good.
1- The parking brake handle is moved up, to let you know the parking brakes are engaged ( unlikely if they are original)
2- There is a pressure differential in the brake system from a leak. Many think the switch plumbed in line with the Master Cylinder is a proportioning valve, it is not. It simply has a spool in it. Your brake system is divided between the front and back brakes. If a leak started in one or the other the pressure changes and the spool shifts making a switch to light the dash light.
You can check to see if the switch for the PB handle is still good and not stuck closed, if good check the M/C to see if one chamber is lower or empty. Look around the calipers for fluid. If that is the case you need a good brake job with new calipers or rebuilding yours if SS lined, new hoses if over 8 years old and don't forget the copper washers for the front hose to caliper connection. If the brakes are hard and even, no fluid seen your brakes should be good.
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Hi and welcome!
The 'BRAKE' light in the dash serves two functions. it will go ON if there is a problem in the service brake system or if the parking brake handle switch is out of adjustment.
Follow the master cylinder hard lines down to the 'VALVE' and remove the TAN wire.
With the key ON see if the 'BRAKE' light is on or off.
If off then the problem is in the valve.
If the light is still ON then the problem is under the console and the parking brake switch is bad or out of adjustment.
Follow the master cylinder hard lines down to the 'VALVE' and remove the TAN wire.
With the key ON see if the 'BRAKE' light is on or off.
If off then the problem is in the valve.
If the light is still ON then the problem is under the console and the parking brake switch is bad or out of adjustment.
