Mechanical brake light switch installed!

[pmajka]

Wakeup call: Almost getting tagged from behind, Other driver said my brake lights were not on..

Car: 1988 911 Carrera
Problem: brake light comes on late in braking and then installing new hydraulic switch doesn't help.

Time to completion: bout an hour

Parts
some copper water pipe
2 x 1inch diameter hose clamps
Length of wire (as needed, i used double insulated 12gauge speaker wire)
2male and 2 female blade/crimp connectors

1 GP Sorensen SLS62 Stoplight Switch 1978 Chevy 1500 brake light sw without Cruisecontrol.


Special tools
wire cutters
wire crimp/stripper
bludgeoning device (hammer preferred)
some socket wrenches

Step 1:
remove foot rest under the pedals

step 2: find round brake linkage that glides next to a Flat rod. should be about diameter of the copper pipe, goes up.

step 3: cut 2 lentghs of copper pipe the width of a Hose clamp. about a 1/2 inch long.

step 4: smash 1 of the pieces of copper pipe flat.

step 5: Pre-bend the hose clamp: get a 3 - 6" piece of copper pipe and tape it behind the Brake linkage rod, then get one of the hose clamps, wrap it around the copper pipe with adjusting nut to the right of the rod. Tighten till very firm and then Back it out...remove the prebending pipe you used, leaving the hose clamp on very (VERY) loose

step 6: install Switch...take 1 supplied adjusting nut that came on the switch, screw it on, followed by the round copper pipe that you cut followed by the 2nd adjusting nut. (the round copper pipe adds structural integrity to the switch so you dont crush the plasitc). Now take the smashed piece of pipe and tape it to the round copper pipe. This will be a spacer that goes against the Brake connecting rod. Slip it into Hose clamp and tighten. Make sure the electric connectors are pointing up. Snug it up but dont tighten it all the way...Yet.

step 7: take 1.5" of copper pipe and smash it flat, then bend it into an "L" mount the with the other Hose clamp o n the Flat bar that is next to the Brake connecting rod. The L should Press the actuator switch almost all the way in. Crank the hose clamp down, but dont strip the hose clamp (i have done that before )

step 8: pop trunk and remove carpet and that board to get to the hydraulic switches..probably have to pull 2 Fresh air hoses too.

step 9: Determine which of the 2 crappy hydraulic brake light switches works best. Find the wires to the brake light switches pull one off, hop in driver seat and press pedal (make sure you can see the brake lights come on!). get a feel for when it comes on and then put the one back on and pull the other off. the one that works better is the Keeper.

step 10: on the front of the master cylinder are 2 plastic covers covering 2 holes. fish a length of wire down the hole, should drop by the brake pedal. crimp and wire female blades to the switch. in trunk, run wire safely to the pulled brake light switch wire and crimp and wire male blades to New installed wire and plugin to pulled brakelight switch wire.

step 11: back in drivers seat and press brake pedal to see if brake lights come on sooner. Adjust mechanical switch on brake linkage rod to where ya like it. Tighten up mechanical switch. Dont crush it...it may spin around a little if you give it the old 3 grunt twist...but otherwise it should not move.


Reassemble Car and Feel safer.


Sorry, i didnt take photos, started to rain.

[450knotOffice]

This looks like an excellent idea. I'm replacing my brake light switches right now and if they still don't work very well then I'll probably go with your technique.

Thanks!

[movin]

Why can't somebody find a more sensitive hydraulic switch? Seems to me something is very wrong with the replacement switches if they still require effort like Godzilla pushing on the pedal. Doesn't this seem odd? Original swithces worked just fine for, say 15 years, then when replaced the new switches are crap!

[pmajka]

i am wondering if that little air bubble that you are going to get in the switch is the cause.

perhaps, we need to put a drop or 2 in the hole first to wet the area.
maybe surface tension of the fluid will pull more fluid in and let any air out. or does bleeding the smack out of brakes do anything?