Adjusting Brake Light Switch, 1930 'oval' coupe

[Diastole]

Good Morning,

Does anyone know how to adjust a brake light switch on an early 1930 coupe?

I have to be pushing the brake pedal over 1" for lights to come on. The first 7/8" of braking does not energize the lights.

My switch is mounted to the crossmember. Bulbs work. Ground is good.

Thanks in advance,

Diastole in the Smokies

 

[old31]

Its hard to tell from the photo but try this.

Shim out the switch with washers or a nut so that you move it further away from the frame. That will move the plunger away from the brake rod.

 

[Sport King Eric]

I took mine apart (just remove from the car and remove the cover) its a simple copper contact that when you push the pedal it a block moves allowing the contacts to touch, some simple bending will allow this to happen. just remember no pedal nothing touches press the pedal the contacts touch.. simple but very effective ..

 

[Will N]

Its hard to tell from the photo but try this.

Shim out the switch with washers or a nut so that you move it further away from the frame. That will move the plunger away from the brake rod.

Agreed. The switch is "normally on" and the brake rod holds it in the off position. Shimming it will move it closer to the on position.

 

[katy]

It looks like their is a carriage bolt in the linkage instead of a proper pin, replacing it w/a pin may take some of the slop out of the linkage, improving actuation timing.

 

[Big hammer]

It looks to me like the switch is a cheaper (15.00$) without a brass bushing ? Purchase a new 50.00$ switch with the brass bushing for trouble free operation !

 

[The Master Cylinder]

Why not just adjust the length of the rod between the brake pedal the cross shaft arm instead of adding washers and bending things? There is a clevis threaded on the end by the brake pedal.

 

[Bob C]

I think he will need to make sure the brake rod arms on the cross shaft are vertical then adjust all the brake rods to get the arm that the pedal rod is on to be more vertical. Now he would be able to shorten the rod from the brake pedal.

 

[The Master Cylinder]

I think he will need to make sure the brake rod arms on the cross shaft are vertical then adjust all the brake rods to get the arm that the pedal rod is on to be more vertical. Now he would be able to shorten the rod from the brake pedal.

Yes, that would be correct except I would adjust the pedal rod to get the cross shaft arms vertical, then adjust the service rods. Right now we don't know if his brake rod arms on the cross shaft are vertical. Could be shortening the rod from the pedal will bring the brake rod arms on the cross shaft vertical.

Regardless, I think the brake rod arm is adjusted too long. My point was to do it the correct way instead of adding washers and benting rods. But I guess that's just me.

 

[Rob Doe]

I'm not sure about 28-29's. For the 30-31s, the face of the button at the end of the pedal to x shaft rod should be 1/16th of an inch in front of the forward face of the back side of the x member. At that position, the outer brake rod levers should be perpendicular to the fame. The button face that pushes on the switch actuating rod must be perpendicular or the rod will bend under repeated loads and hang up.

The button was not parallel to the face of the x member as stated on our car. The cheap switch rod bent and even hung up the pedal on our coupe. I had to roll the pedal rod over 180 degrees to get a better alignment of the button face. The issue has not returned in 20,000 miles. I wipe a dab of oil on the switch rod, front and rear, occasionally to quiet the squeaking. I use a board between the seat base and the pedal to access the front side of the switch rod. Be forewarned, if the board slips or your helper's foot slips, you'll have a very smashed set of fingers. Use a brush to wipe the oil on the rod?????

The arm on the x shaft should be ~ 10-15 degrees tilted to the rear when at rest. This allows for max leverage when the brake pedal is fully depressed. (about 2 inches from the floor minimum) The x shaft lever is then perpendicular to the pedal rod which is max leverage.

 

[GeneBob]

I did what poster #2 is suggesting. I put a washer between the switch mounting pad and the frame. This moved the switch away from the brake rod a little bit.
If you have actual braking happening in the first 7/8" of travel, I am impressed.

 

[Diastole]

You guys are awesome!!

Thanks for all the advice. I took the switch off and examined it. I could grind down the shaft a bit, or take it apart and bend the contacts like one post suggested, or shim it with washers. The least dramatic, most easy, and less destructive was the shimming.

See Pictures

It worked great. I now have wonderfully responsive brake lights. I was in the parade yesterday, and they guy following me said everything worked perfectly. I sighted The Ford Barn as the resource that fixed my brakelight switch.

I appreciate ya'll

Diastole in the Smokies