Carrera brake light pressure switch questions

r-mm · 08-24-2014, 02:23 PM

The brake lite switch(s) are inop on my 87. I've removed a few hoses and other things to get reasonable access to them. By jumping the female end of the connectors of the frontmost switch, I get the brake lites on. Because the rear one looks like a royal PITA, is there a reason to replace it as well? If the answer is YES then any tips on how to get it in/out? A deep 22mm looks viable for the front switch... but the rear?

While I'm ordering, wondering if there are other common little annoying (but potentially serious) problem areas like this. Motor is fully rebuilt including all electronics so I'm good there. Opened the doors to fix snapped lock actuators... did some work on the sunroof hinges. Any other common annoyances?

ganun · ganun's Garage

Use this german wrench for the rear. Change both, cheap.

kjchristopher · kjchristopher's Garage

Quote:

Originally Posted by ganun

Use this german wrench for the rear. Change both, cheap.

What he said. I happened to have a 7/8" (22.2mm) wrench shaped like this and used it.

wrxnofx · wrxnofx's Garage

I JUST did these last week on my 87. I didn't have one of the wrenches above. I removed one of the hoses (the short one) and disconnected the left side of the long one to push it out of the way. That gave me enough access. I did not remove any other aspect of the fresh air blower.

The front one was easy. A 22 mm deep socket works great. Put a rag underneath the switch and put the new one in quickly, as you will leak some brake fluid out of the master cylinder.

For the back one the deep socket was too deep. I used a regular 22 mm socket, universal socket, and extension. The 2 poles of the connector stick into the 1/2" square of the 22 mm socket, so you can't fully push the universal socket into the 22mm socket.

No need to bleed the system, but you will have to replenish the lost brake fluid. The new switches make a world of difference in the amount of effort and pedal travel to get the lights to work. Change both. Since you have the '87 like me you'll need the 2 pole switches, not the 3 pole version.

emac · emac's Garage

You will only loose a few drops of fluid.

r-mm · 08-25-2014, 04:05 AM

Thanks everyone, I have two switches on order and have removed the parts mentioned for access.

Elsewhere on pp 24mm is mentioned. Are the 2prong switches for my car 22mm or 24?

KTL · 08-25-2014, 08:14 AM

Also note that the switch threads are 1/8 NPT. So don't keep tightening harder and harder, expecting the connection to "bottom-out" and be fully tight. The thread body is a tapered fit, so the male threads of the switch are trying to spread open the female hole in the master cylinder

$ Short · $ Short's Garage

I just put larger MC in my 88. I had to start the car and let run( vacuum assist) and then I had brake lights. I did search and this was suggested. Good luck
Kurt

wrxnofx · wrxnofx's Garage

Quote:

Originally Posted by r-mm

Are the 2prong switches for my car 22mm or 24?

22mm

r-mm · 08-29-2014, 06:35 PM

Thanks all. I installed two new sensors from PP today. Marked ATE, made in Czech Republic FYI. Used these offset wrenches from Harbor Freight which fit so well it was almost as though they were designed for the job. The offset box wrench works so well for both I wouldn't bother with a deep 22 socket if you don't have one. I primed both switches and the brake lites now come on with quite low pedal pressure. Not modern honda hair trigger but certainly nothing I'd call unusual.