Brake light switch

[Sonny]

I’ve been through 3 brake light switches and now need a 4th. My original broke, then my autozone switch broke, and now the Napa switch broke. They mechanically come apart from pedal wear. Can anyone point me to a decent switch for a ‘70 b body with power brakes?

 

[Sonny]

I’ve been through 3 brake light switches and now need a 4th. My original broke, then my autozone switch broke, and now the Napa switch broke. They mechanically come apart from pedal wear. Can anyone point me to a decent switch for a ‘70 b body with power brakes?

These are the ones I used-

 

[Kern Dog]

I use a different one than that in both of my Chargers. Mine is about 3/4"in diameter.

See the pink and white wire attached to the end?

The car in the picture was a manual drum setup that now has a 75 Dart brake booster and MC. Those systems have all the bellcrank linkage on the engine side. Factory B body power brake cars do have that funky reduction linkage under the dash but I don't know if that necessitates a different switch.

 

[pnora]

I’ve been through 3 brake light switches and now need a 4th. My original broke, then my autozone switch broke, and now the Napa switch broke. They mechanically come apart from pedal wear. Can anyone point me to a decent switch for a ‘70 b body with power brakes?

That is a very basic switch. They seldom fail. Most were replaced for no reason. How are they breaking? My bets your pedal is not set up right and it is slamming back on the switch. The pedal needs a stop and it is not the switch.

 

[Kern Dog]

My brake pedals don't have any sort of "stop".

 

[pnora]

My brake pedals don't have any sort of "stop".

They should. Or have some type of adjustment either on the pedal or switch to keep it from breaking.

 

[Kern Dog]

My point was that no cars that I own have what you are suggesting.

 

[dadsbee]

Only brake "stop" on a B body is the linkage itself.. clutch pedal is another story.

 

[Nacho-RT74]

I can't recall a stop bumper either on my brake pedal assembly. Just on my emergency brake pedal. Of course, auto car.

 

[Durandal25]

They should. Or have some type of adjustment either on the pedal or switch to keep it from breaking.

***This*****

 

[64Bob]

I'm having the same problem with my '64 Plymouth. I've replaced three stop light switches and have two ordered. It seems the switch is also the stop for the pedal, but after applying the pedal a few times the switch is either pushed out of the bracket or it brakes. I was told that the bracket has two different mounting positions, one for power brakes one for manual. To move the bracket you need to unbolt the bracket and move it into the other holes. Hope to try this when I have the new switch. Will keep you posted.

 

[Nacho-RT74]

They should. Or have some type of adjustment either on the pedal or switch to keep it from breaking.

no, pedal brakes don't have any kind of adjustment for anything.

The only adjustment available is at the pushrod on engine bay side pushing the MC for the brake response.

And at the switch bracket for the brake lights response. Bracket can be adjusted to front or rear for this.

but, PEDAL ITSELF doesn't have any kind of adjustment, stop, or anything. They remain free of movement if you remove the MC being manual brakes or Booster if powered.

 

[Ron H]

When switch is breaking, what is the damage? Bent/broken plunger, tip, etc? If the switch is off center or tilted too much up/down from the pedal arm this can cause undue side pressure on the plunger. There should be a slight amount of free-play when the pedal is in home position. The switch shouldn't be acting as a pedal ‘stop’.

 

[Nacho-RT74]

A body shown... but similar to the rest

 

[pnora]

no, pedal brakes don't have any kind of adjustment for anything.

The only adjustment available is at the pushrod on engine bay side pushing the MC for the brake response.

And at the switch bracket for the brake lights response. Bracket can be adjusted to front or rear for this.

but, PEDAL ITSELF doesn't have any kind of adjustment, stop, or anything. They remain free of movement if you remove the MC being manual brakes or Booster if powered.

It is how you are interpreting my answer. Point being there should be a form of a stop to keep the pedal from smashing the switch. In this case the linkage or rod should have a limit as to how far it can return. If the poster in this case has the possibility of several issues. 1-Mis-adjusted switch. 2-Mis-aligned switch. 3-Excess pedal return commonly no grommet in the rod locking it into the masters piston.

 

[LJR 70]

going to jump in here. 70 GTX
Currently working on same problem. I don't have a stop bumper on brake pedal, but can adjust length by running switch up or down on its threaded housing. Looks like there are 2 different wiring set ups. Mine is same as Kern Dog pic's. Has an open set of contacts that closes when pedal depressed and I want to say Nacho's grounds out the circuit. Interesting that its listed as "Without cruise control" vs "Heavy duty"

 

[Sonny]

going to jump in here. 70 GTX
Currently working on same problem. I don't have a stop bumper on brake pedal, but can adjust length by running switch up or down on its threaded housing. Looks like there are 2 different wiring set ups. Mine is same as Kern Dog pic's. Has an open set of contacts that closes when pedal depressed and I want to say Nacho's grounds out the circuit. Interesting that its listed as "Without cruise control" vs "Heavy duty"

View attachment 1204091

Thanks everyone. Replaced with the heavy duty version.