Brake Warning light

[Jamiez]

When I had the challenger out for it's first cruise of the summer, the brake light came on.  Previously, I had only seen this light when the parking brake was engaged.  The car seemed to drive and stop fine but it was a very short trip and at low speed (local roads).

I've tried various manipulations of the parking brake pedal and the light remains lit, I went through the service manual flow chart.  The master cylinder is well over half full, the pedal is low and firm (not low and spongy or all the way to the floor).  At that point the manual says "Adjust Brakes, Check Linings"

I'm wondering how I should proceed from here...i.e. what should I be inspecting/removing/replacing/etc.  I've never really done anything with brakes before, although they were on my list to give a once over this year.

[ChallengerHK]

There is a switch in the proportioning valve that can get stuck in one position that leaves the brake light lit. I've had this for years. Personally, I ignore it, until the day when I replace the valve. Of course, this might not be the problem you have 

[72rtchallenger]

if its not the proportioning valve then inspect everything,,check all your lines and brake cylinders for even the smallest leak,,you could try and adjust the rear shoes and bleed the whole system and see if it goes out,,or you might want to check the switch at the pedal first, make sure its functioning and no wires off

[Jamiez]

So...how would one check the proportioning valve?

[ChallengerHK]

I don't think there's an easy way. that's why my brake light is still lit 

[Bullitt-]

To reset the switch you just hit the brake pedal hard, that is if there is no other reason for it to be on.

[ChallengerHK]

To reset the switch you just hit the brake pedal hard, that is if there is no other reason for it to be on.

I've tried that, Wade, but it didn't work for me. On the other hand, mine sat for years, so I might have other issues.

[Jamiez]

For stomping on the brakes.

Power brakes, does the car need to be running?  I hope it doesn't have to be moving......

[Bullitt-]

For stomping on the brakes.

Power brakes, does the car need to be running?  I hope it doesn't have to be moving......

When I reset mine I had it running, not moving. This was after a complete overhaul of the system.

[Jamiez]

Stomping on the pedal with the engine running didn't work. So I took a look at the prop valve...there are no obvious leaks.  However there is a connector with 2 black wires.  One goes to the prop valve the other into a larger harness....but nothing plugs into the connector itself.

In the picture it is in the upper right, just above the red wire.

[Bullitt-]

The extra wire is a test hookup, no effect on normal operation.   Have you studied your parking brakes switch real well? Those can get out of adjustment & stay in the closed position. You can also unplug either of the switches to find out which one is keeping the light on.

[Jamiez]

No that's next, I figured I'd check the prop valve for anything obviously wrong (leaks etc).  I ended up staying at work late and crawling around down there wasn't high on my list of things to do this evening.

What does the testing outlet typically read?

[Bullitt-]

I've only read about the testing outlet and don't recall it's use being described. I would assume that you provide a ground through it to check that the light in the dash would illuminate or possibly add a light or meter to see if it shows a closed circuit (switch) in the case of the dash not lighting.   

[Jamiez]

And now the light is off......yeah...that fills me with confidence....I'll be giving it a complete going over before I take it out again

[Bullitt-]

I've got the same issue with a Dakota P/U... On sometimes off sometimes, the brakes work fine and there seems to be no reason for it so I don"t worry about it anymore.