Hey guys. So...the brake lights on my 89 are working but I have to push the pedal pretty far before they come on. When the engine is not running, I barely have to touch the pedal for them to come on. When it is running, I have the above issue. Could it be that the master cylinder's leaking is causing the pedal to travel too far for the brake light switch or is there a way to adjust the switch sensitivity??? Any help is greatly appreciated. This thing is buggin me like crazy.

 

Where is the switch for the brake lights? Is it in the master cylinder? Or is it under the dash by the pedal?

 

It's under the dash by the pedal.

 

If the Master Cylinder is leaking, that needs to be fixed, but the 2 problems shouldn't be related in my opinion. Could the switch be sticking by the pedal?

 

it's almost as if the spring between the pedal and the switch is too heavy. And I've lubed it up with WD40 so I doubt it is sticking

 

The brake light switch is located on the brake pedal.

9C962 in pic is used with Speed Control.

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Ok...but I'm not sure if that helps me with the problem. Could a worn out booster cause this issue?

 

Don't see how. It has to be electrical. Either in the switch, or there's a drain somewhere in the wiring causing the current to be sent somewhere else other than the brakelights. Does your truck have a 3rd brake light? The light on the back of the cab?

 

Nope. They didnt start putting a third brake light until 1992 and up. When I look under the dash with the motor running, it looks as if the booster shaft that is attached to the pedal is not pushing back against the pedal hard enough to compress the spring on the light switch.

 

Hey guys...So...I fixed the issue with the brakelights. I just put a softer spring in the switch. I looked at all the options I had and I decided that I didn't want to risk getting rear ended. Thanks for all the help.