KPumroy
Member
So continuing the brake saga with my 1968 Charger. I had recently reworked the rear drum brakes as they were sticking and grabbing. When I had my car transported south the driver used the parking brake which seized the rear brakes up. This got me working on the rear brakes which is another story. This story is about the front disc brake conversion I had done about 20 years ago. I had a shop install a front disc brake kit with power booster, new master cylinder and combination valve. I was never impressed with the feel of of the brakes and know I know why. While working on my rear drums I cut the parking brake cable, I know I have already caught flack for that. But, I noticed there was no brake light warning coming on on the dash. I was going to disconnect the switch at the parking brake lever arm so the light wouldn't come on but there was no light. Seems someone had pulled the light bulb out of the dash and the bulb was on but illuminating an empty void behind the dash. So the brake warning light was on even though I had disconnected the parking brake switch. So next I checked the switch at the brake combination valve and guess what, there was continuity at the switch. I pulled the switch and looked into the valve and the shuttle valve had closed off the rear brake circuit. Looked online and some had suggested using a little pick tool to reset the shuttle valve. That was unsuccessful. So I replaced the brake light warning bulb in the dash and started the car, pumped the brakes up then firmly pressed the brake pedal, very firmly. I heard a little click and the brake light went off. The valve had reset! I then went around and bled the brakes with a vacuum bleeder. Wow what a difference! The brakes feel great and the car stops on a dime. So I surmise 20 years ago the mechanic didn't use the little tool that you are supposed to use to lock that shuttle valve open while pressure bleeding the brakes and for 20 years I have had little or no rear braking. The sad part is that he had artfully hidden the brake light warning bulb so I had no idea. Hopefully this will help others as those combination valves are a commonly misunderstood part of the brake system.