W123 240D Brake Light Switch R&R Tips? - PeachParts Mercedes-Benz Forum

nategodin · #1 02-16-2013, 04:45 PM

Hello,
I need to replace a failed brake light switch on my 1982 240D. I'm having a heck of a time removing the old broken one (snapped the base clean off the longer threaded part), literally have to bend over backwards to get at it, and there isn't much room for wrenches with the pedals and steering column in the way. Does anyone who's done this before have any tips on how to get the old broken switch out of there? I'm about ready to take a small reciprocating saw to it, but maybe there's a more elegant way. Do I need to do anything special to adjust the new switch before/during installation?

Thanks,
Nate

nategodin · #2 03-26-2013, 09:42 PM

Anybody? I would really appreciate some advice from somebody who has tackled this job before. I've just about given in to the idea that removing the driver's seat (or finding a good chiropractor) is an absolute necessity.

Thanks,
Nate

bricktron · #3 03-27-2013, 01:54 AM

lay some cushions/blankets down there and you will be more comfortable. removing the seat sounds smart. good luck!

whunter · #4 03-27-2013, 03:24 AM

Quote:

Originally Posted by nategodin

Hello,
I need to replace a failed brake light switch on my 1982 240D. I'm having a heck of a time removing the old broken one (snapped the base clean off the longer threaded part), literally have to bend over backwards to get at it, and there isn't much room for wrenches with the pedals and steering column in the way. Does anyone who's done this before have any tips on how to get the old broken switch out of there? I'm about ready to take a small reciprocating saw to it, but maybe there's a more elegant way. Do I need to do anything special to adjust the new switch before/during installation?

Thanks,
Nate

Being a big guy myself.

The easiest way is to remove the driver seat.
I lay rubber mats on the car floor.

.

nategodin · #5 03-28-2013, 08:10 AM

Thanks, guys, will tackle this job today if I can get away from the day job for a few hours!

nategodin · #6 03-28-2013, 09:55 PM

Well, I don't know if it was necessarily the best way to do it, but this is how I got the job done... first, take the driver's seat out. Get a couple 17mm wrenches and a flashlight and lay on your back with your head under the steering wheel. Get comfy, you're going to be there a while! Get your first 17mm wrench up under the dash, above the steering column, and hold the nut on the pedal side of the switch stationary. Then, with the other 17mm wrench, back the other nut off, towards the base of the switch (as I mentioned before, the base of my switch broke off, so it kinda looks backwards). After a while, it will catch at the bottom of the switch. Keep turning the nut, and it will start backing the whole nut/switch assembly out of the nut you're holding in place with the first wrench. My ratcheting wrenches weren't skinny enough to fit in there, so I had to do a quarter turn or so at a time, taking frequent, brief breaks to let the blood flow back into my arms. Eventually, the switch/nut assembly, nut, and serrated washer will come free, and if you're very lucky, none of them will fall on your face and poke you in the eye in the process. You will need to remove the other nut from whatever is left of the switch... I found clamping it in a vise to be helpful. Then, take your new switch, and get the first (closest to the base of the switch) nut adjusted so that the switch is just barely open when the brake pedal is at rest. Put the second (closest to the brake pedal) nut and washer in place, hold them still with a 17mm wrench, and turn the switch until the switch is in the correct position. Then, take your other 17mm wrench, and tighten up the first nut. Re-connect the plug to the base of the switch, test it out, and pray that this one will last another 30 years! (You did get the Genuine Mercedes switch and not that Spanish FAE crap, right?)

Hope that made sense!

Nate