Question regarding '68 brake light switch

[ltdmstr]

The factory repair manual shows the '68 C10 has a button type brake light switch mounted on the pedal arm inside the cab. My truck had a pressure style switch on the front of the master cylinder. Does anyone know if the mc mount pressure switch is a factory setup, and whether there should be a mount inside on the pedal arm? The reason I'm asking is I replaced my manual brakes with a disc/drum setup and new mc with hydroboost and the new mc didn't have an outlet for the pressure switch. I know I could have mounted one inline somewhere, but I thought a mechanical switch would be better and at this point I don't want to mess with the brake lines to add one. So I'm going to use the button type mechanical switch and am thinking I need to figure out a way to mount it. But if there's a tab or something in there already, I'll find a way to get at it.

[72c20customcamper]

Think gm stopped using hydro pressure switches in the early 60e. Doesn't sound right on a 68

[70STOVEBOLT]

If you are talking about the brake warning light switch it is mounted on the distribution block on 4 wheel drum brake trucks and on the proportioning valve on disc brake trucks, both by the master cylinder. The button switch you are referring to is the brake light switch that activates your brake lights. All trucks have this mounted under the dash in contact with the brake pedal arm.

[72c20customcamper]

Look like this ? Very familiar with these my Studebakers and Harleys use them or is it just a single line coming from the portioning valve

[ltdmstr]

I'm referring to the switch that activates the brake lights when you hit the pedal. The truck had a single wire pressure switch like the one in the photo above. I'm planning to use one that looks like this. The factory chassis repair manual at page 12-11 shows this type of switch mounted on the pedal assembly.

[70STOVEBOLT]

That is not a pressure switch, it simply completes a circuit when you push the brake pedal.

[ltdmstr]

I eliminated the pressure switch when I replaced the master cylinder. So, right now, now I don't have a switch and don't have any brake lights. I want to use the mechanical switch shwon above instead of a pressure switch. The drawing in the factory service manual shows this type of manual switch mounted on the pedal assembly. So I'm trying to find out if there's a place to mount it somewhere up in there that I can't see. If there's a factory mount, I'll probably start taking stuff apart until I can get to it. If not, I'll have to figure out a way to mount it.

[Andy4639]

The first pictures are of a pressure switch for the brake light in the dash. If the front/rear brakes have a problem the light will come on due to more pressure on one side than the other basicly.

The push button switch in the last picture is the one used on the brake pedal to activate the brake lights on the rear of the truck. The picture I used is of a mod I did to my e brake to light up the dash light if my e brake is engaged.
It works the same way though.

[ltdmstr]

You're saying the truck would normally have both switches? I don't recall seeing anything like the one in the third photo on my pedal assembly. And I was up there replacing the clevis for the mc push rod. Not sure if it matters, but it's a straight 6 with column shift 3 speed. So things are pretty tight.

[LockDoc]

Originally Posted by ltdmstr

I'm referring to the switch that activates the brake lights when you hit the pedal. The truck had a single wire pressure switch like the one in the photo above. I'm planning to use one that looks like this. The factory chassis repair manual at page 12-11 shows this type of switch mounted on the pedal assembly.

That is the switch you need and here is where it mounts. There is a small bracket in between the sides of the main pedal bracket. One of the pressed steel nuts will be above the small bracket and one is below. It is hard to get to unless you drop the steering column down to install it. You adjust it by screwing the bottom nut where it needs to be for the switch to operate correctly and then snug up the top nut to lock it in place.

The wiring connector should be there somewhere. The wires in the plug would be Orange & White.....

LockDoc

[ltdmstr]

Thanks much for the photo. I'll check mine tomorrow when I get to the shop. If that's what's supposed to be there from the factory, then it should already be there. And if that's case, I just need to get them wired up and should be good to go. I appreciate the help!

[Andy4639]

I knew I had picture of it. Here is the brake pedal in my 68 I sold. Automatic with the NSS on the column. The 3 speed want have it. I took the 3 speed out and installed a auto tilt in it's place.

[ltdmstr]

Turns out the factory switch is up there and working fine. I installed a new rear harness and have brake lights again. So I'm finally back on the road after spending the whole summer working on the truck. Really glad I don't have to get in there to replace the switch. Only downside is I don't have the pressure switch for the warning light, but that's not a big deal. Just did a bunch of updates so I can drive it while I finish some other projects. It's eventually going to get a complete teardown and rebuild. Thanks for the help!

[70STOVEBOLT]

Glad you got it worked out, now you can enjoy driving it

[Andy4639]

Originally Posted by ltdmstr

Turns out the factory switch is up there and working fine. I installed a new rear harness and have brake lights again. So I'm finally back on the road after spending the whole summer working on the truck. Really glad I don't have to get in there to replace the switch. Only downside is I don't have the pressure switch for the warning light, but that's not a big deal. Just did a bunch of updates so I can drive it while I finish some other projects. It's eventually going to get a complete teardown and rebuild. Thanks for the help!

Good deal. Glad it's back on the road. Keep them running.