Hey there, I just recently picked up a ‘99 Suburban that’s got a lot of work to be done. One issue I’m running into is not having brake lights light up. I know what is wrong, just don’t know how to fix it. The problem Is the brake switch (which I have replaced) is not engaging with the pushrod. The switch works when I manually push the switch contact onto the rod. The clip that holds the switch in place has been replaced with an oem clip, and the switch contact still does not hit the pushrod. I’ve tried pushing the clip in farther, no change, all connections are secure and solid, and even disconnecting the master cylinder and pushing the pedal to the floor does not make contact with the switch. So I don’t know if the rod on the pedal where the switch slips on is messed up or what. Do I need to just get a new pedal assembly from the junkyard? Just to reiterate, it is not an electrical issue, just a mechanical issue with the brake light switch and pedal. The lights all work when I manually push the switch with my hand. Thanks in advance, everyone.

 

Post some good pictures, clear and close. You should be able to fix up something. Is yours a switch that's normally "open" and pressing the pedal down is supposed to "close" (complete) the circuit? and light up the brake lights??

Some "foreign" trucks use a plastic plug to actuate brake lights, and once those break, the fix is to epoxy in a penny.

 

Yes, it is the old body style brake light switch, I have a pic of it here. I noticed the pushrod has an indent ( don’t know what else to call it) where the brake switch snaps onto the rod. Could that be worn down enough for the switch to move completely with the pedal?

The switch I’m using

This is looking straight up to the switch from the floor.

Directly behind the pedal facing away from the firewall


From the floor without the switch on the rod

Facing away from the firewall w/o the switch on the rod

 

So I still haven’t solved the problem yet, but I have come up with a solution for the time being. I tied some insulated speaker wire around the brake switch to the steering shaft and that engages the brake switch to make the lights come on with the pedal. The downside to this is that you lose some of the sensitivity for the brakes because the wire is not allowing the pedal to travel like it should. Just making slower, earlier stops for now. My guess for the source of the problem lies in the brake booster rod coming through the firewall. It seems the pushrod doesn’t have a defined edge for where the switch is supposed to rest and pit against to make the switch stationary, therefore engaging the switch and closing the connection when the pedal is pressed. If anyone thinks the brake booster pushrod may be the issue, let me know, ‘cause I’d really like this to work without sacrificing brake pedal power.

 

Have you figured this issue out Yet? I’m going through the same thing rn. Brake switch doesn’t seem to fit real snug or tight and when I touch the pedal the brake light comes on but turn off when fully pressed

 

Final result was that I ended up having to replace the whole brake booster to fix the issue. I don’t know if the rod just got worn out and bent over time, but it’s kind of silly and not cheap for what should be a simple fix. That’s what it took to fix my issue, not sure if it’d be the same for yours. Good luck though!