Brake lamp came on
Thread Starter
Melting Slicks
Joined: Jul 2008
Posts: 3,202
Likes: 1
From: Fairview, GA
Brake lamp came on
A couple of days ago I did a trans service on my car (84 4+3 Z51). I had the ebrake on while on the rack. After I dropped the rack and got in to back it out I noticed the brake lamp on. I operated the handle a couple of times, and over the lest 4 days have used it repeatedly. My brake pedal is still perfect, brakes don't get hot, not leaking fluid, ebrake works & releases fine but the lamp stays on. I looked at the lift points I had the rack at and all looks okay, no visible damage. Any ideas? Thanks.
Pro
Joined: Oct 2005
Posts: 541
Likes: 1
From: Freeport FL
Well I dont know anything about this, but it seems obvious to me that there is a switch that senses when the parking brake is engaged, and that it has gone bad or become disconnected. But I dont know where it's actual location is. Someone with a little more experience in that area will have to chime in. Id guess it's somewhere near the handle, but that would be a guess.
Assuming you know that the PB is disengaged without a doubt, I dont think I would lose any sleep over it in the meantime, especially since you have checked everything else out.
The light could also be made to come on by a pressure imbalance in the F/R brake systems, but this doesnt really sound like that. USually thats caused by something like a large loss of fluid, like disconnecting brake lines during maintenance, etc. Sounds to me that you've checked things out to preclude this.
Assuming you know that the PB is disengaged without a doubt, I dont think I would lose any sleep over it in the meantime, especially since you have checked everything else out.
The light could also be made to come on by a pressure imbalance in the F/R brake systems, but this doesnt really sound like that. USually thats caused by something like a large loss of fluid, like disconnecting brake lines during maintenance, etc. Sounds to me that you've checked things out to preclude this.
Thread Starter
Melting Slicks
Joined: Jul 2008
Posts: 3,202
Likes: 1
From: Fairview, GA
I thought about the switch at the lever. It should be at the base of the handle, somewhere it can contact the handle when it is dropped. I haven't had time to take anything apart, between work and rain the last couple of days. I looked underneath where I put the lift pads, and only one spot does it come near a brake line (lr) but nothing looks bent or even scraped. I was very careful. I wondered if there was some kind of switch (inertia or some other?) I might have inadvertently triggered. I never had any problem with the lamp before I picked it up, and it just may be a coincidence, but seemed odd. Everything seems okay, I've been driving it, no pull anywhere, brakes are perfect. The lamp just drives me nuts! Thanks for your input.
Pro
Joined: Oct 2005
Posts: 541
Likes: 1
From: Freeport FL
The pressure (imbalance) switch is in the brake proportioning valve down on the frame. I suppose that you could unplug the wires and/or short them (depending on if its normally open or nomally closed. I would asume its normally open, a wiring diagram would show). You could then rule that out. I find they are pretty hard to trip though unless you have some sort of major issue going on. But its worth checking.
As far as the one by the parking brake handle, I looked it up in the Helms manual for you. It is located on the inboard side of the parking brake handle aassembly.
Speaking of which, you should probably look into getting a Helms if you dont have one. Not cheap, but worth it. I picked mine up on here about half-price.
As far as the one by the parking brake handle, I looked it up in the Helms manual for you. It is located on the inboard side of the parking brake handle aassembly.
Speaking of which, you should probably look into getting a Helms if you dont have one. Not cheap, but worth it. I picked mine up on here about half-price.
Last edited by Droshki; Nov 25, 2008 at 10:32 PM.
Pro
Joined: Oct 2005
Posts: 541
Likes: 1
From: Freeport FL
Looked up the wiring diagrams for you.
Brake pressure switch is normally open, closes with unequal system pressure.
Parking brake switch is normally open, closes when parking brake is on.
Unplug each one.
Note when light goes out.
Problem resolved?
Brake pressure switch is normally open, closes with unequal system pressure.
Parking brake switch is normally open, closes when parking brake is on.
Unplug each one.
Note when light goes out.
Problem resolved?
Last edited by Droshki; Nov 26, 2008 at 11:23 AM.
