brake light on dash won't go off even after stomping

[Kaptain Kadian]

I recently did a front disc swap and still can't get the brake light to stay off. It was off, then I drove it yesterday and it came back on. I can't get it to go off at all now. Any suggestions? thanks

[lifeinak]

Sounds like the switch on proportion in valve is tripped. It sees a unbalance in the two brake zones usually caused when bleeding your brakes. There several threads about this on this site. Try a search, should help. Good luck.

[cdowns]

if you had the service manual you could read it and learn the proper way to bleed the brakes and have the light go off

[VetteVet]

Pull the wire off the proportion valve and check the light (key on) if it goes out the guys are correct. If it stays on the wire is shorted to ground.

[Kaptain Kadian]

Originally Posted by VetteVet

Pull the wire off the proportion valve and check the light (key on) if it goes out the guys are correct. If it stays on the wire is shorted to ground.

I checked that the other day. It goes off when I take the wire loose.

[zosoppp]

If this is the result of a disk brake conversion,was it just front wheel disks or all four wheels.

It might be that you need to replace the old prop valve (and MC) with one specifically meant for Disk/drum systems instead of the drum/drum it would have started with.

[Kaptain Kadian]

I replaced the proportion valve with a disc/drum one.

[jocko]

Things to check - am sure you've already done this though: Both rsv's of the mc full? Checked rear wheel cylinders for leaks? The sensor is tripped, that's a given. Only way I know to reset them, without the tools outlined in the shop manual, is to do all the above, then when you're certain the system is leak free, stomp on it. And it sounds like you've done that. Did you switch the front lines to 3/16" rather than the original 1/4"? (That SHOULDN'T matter, only affects pedal feel and work accomplished per amount of pedal travel, but I am curious). Did you buy a disk/drum prop valve or factory-like distrib block?

[Fitz]

Originally Posted by jocko

Things to check - am sure you've already done this though: Both rsv's of the mc full? Checked rear wheel cylinders for leaks? The sensor is tripped, that's a given. Only way I know to reset them, without the tools outlined in the shop manual, is to do all the above, then when you're certain the system is leak free, stomp on it. And it sounds like you've done that. Did you switch the front lines to 3/16" rather than the original 1/4"? (That SHOULDN'T matter, only affects pedal feel and work accomplished per amount of pedal travel, but I am curious). Did you buy a disk/drum prop valve or factory-like distrib block?

There is a way to reset them. Remove (carefully) the plastic brake light switch with either a socket or a box wrench. Underneath it is the piston that allows presure to both front and rear brake lines. With an awl or long pick, move the piston to the position shown in the cutaway. That will "reset" the piston then, before applying any pedal pressure, be sure both reservoirs on the master are full.