Brake warning light stays on

willem · Oct 13, 2019

Hi,

My 72 Coronet has a brake warning light that's not going off. I already checked the switches at the pedal and the emergency brake, but those are ok. I checked the reservoir (has 2 sides), and the front side is almost empy. I refilled that, pressed the brake pedal a few times with a running engine, but the light doesnt go off. The pedal feels kinda spungy though.

The car has been sitting for almost 6 years, and it never moved in this time. Does anyone have an idea what this could be?

miller · Oct 13, 2019

Considering the year (72), probably a distribution valve, has switched 'off' the fluid to that pot, that was low.
Do you have a service book, to look up the brake system?

First, I'd suggest, determine if that pot feeds front, or rear brakes. Once known, look them over, for any signs of leaking. There's a reason the fluid was low. Once all is good...
I'm pretty sure, in the distribution valve, there's a 'cut-off valve', and probably has to be moved back to center manually. Then, you should get fluid to both fronts, and rears.

That cut-off valve, was added in the later systems, as a so-called safety feature.

miller · Oct 13, 2019

The brake warning light 'switch' is part of that distribution valve, activated when the cut-off valve moves off center. Once re-centered, light will go off.

66Satellite47 · Oct 13, 2019

Pretty sure the front reservoir is the rear. Be sure to look for any rear system leaks. You need to be sure the system has been fully bled. FSM will tell you about the "manual reset" on the distribution block.

R/T Boy 67 · Oct 13, 2019

You need to go over your entire brake system carefully. You probably have a leak in your rear circuit. Fix that first, and then flush out all of that brown crap that used to be brake fluid. The brake safety switch is probably all crusted up, and will need to be cleaned or replaced. It should self center if it is free to move. The early valves were self centering, and I'm sure the 72 valve is also.

Slotts · Oct 13, 2019

It could be that the insulation on the wire to the proportioning valve has been cut into by something (sheet metal) enabling ground. 12 volts is always active at the bulb socket.

Jim

Dibbons · Oct 13, 2019

Same problem with my '72 Satellite but my brakes are fine, just had to disconnect the wire at the proportioning valve for the light so I would not keeping seeing a false warning on the dash. Some day maybe I can have it rebuilt. The self-centering tricks don't work.

Brake warning light stays on

willem

Well-Known Member

miller

Well-Known Member

miller

Well-Known Member

66Satellite47

Well-Known Member

R/T Boy 67

Well-Known Member

Slotts

Well-Known Member

Dibbons

Well-Known Member

Similar threads