Tuesday, May 4, 2010

Beater How To: Homemade Brake Light Switch

I don't know why my rear brakes aren't building enough pressure to trip the brake light switch but what I do know for damn sure is that I'm not pulling the currently leak-free system apart to find out why. Therefore, I made a brake light switch to both warn drivers behind me that I will be slowing down intentionally and increase driver involvement.

First, I pulled an old momentary switch out of some old broken piece of equipment on the floor. Any momentary switch will work. Even a non-momentary switch will do if you have good short term memory.

I then found a length of 3-wire cable that was both shielded and sheathed. The shielding and sheathing protects from both electromagnetic interference and getting slammed in the hood. Then some female blade connectors were crimped on to two of the wires and connected to the switch. The switch was then zip-tied to the shift lever for easy access.


  1. Just curious what kind of car it is that you must open the hydraulics to fix a brake-light switch. Every car I've ever owned had a simple to replace mechanical switch attached to the brake pedal linkage.

  2. It's an old Simca. I wish it were just a switch so I wouldn't have to even touch anything that carries fluid.

  3. A single reservoir master cylinder is an outdated part with only one reservoir holding brake fluid in it – and the problem with this is that if one component of your brake system fails, you can say goodbye to brakes on all four car wheels. best brake fluid for toyota