Low Pressure Brake Light Switch

[Carnut]

I know most of you guys don't deal with this but there are some that may. None the less, it is still good information.

I lot of older lightweight cars use a pressure switch to activate the brake lights. The problem is because of the light weight, the brake light doesn't come on until you jam on the brakes hard. Lighter applications of the pedal show no brake light. The advantage to having the brake light come on sooner should be obvious.

There is an easy cheap fix. Painless wiring has a switch that activates between 20-50 psi whereas a normal switch is supposed to activate between 60-120 psi.

The switch comes with an electical pigtail.

It took me about 10 minutes to install including the pigtail which I soldered and shrink tube wrapped.

[Joe G]

:goodpost:

[Gr8snkbite]

good data nut...i'm surprised that i require very little pressure before my lights come on in the Cobra...:grin: however, not having power brakes was a neat adjustment having to focus on while driving....gotta love down shifting....may just shift over to power brakes.....and steering..we shall see.

[Carnut]

good data nut...i'm surprised that i require very little pressure before my lights come on in the Cobra...:grin: however, not having power brakes was a neat adjustment having to focus on while driving....gotta love down shifting....may just shift over to power brakes.....and steering..we shall see.

You may have a low pressure switch already if you have a pressure switch. You could have an electric contact switch instead. Some of the guys like manual brakes because the Cobras are usually overbraked and have no antilocks. It's harder to lock them up they say. You should have a pretty light steering feel as light as that Cobra is, somewhere around 2200 lbs I would think.

[Tommy Gun]

Huh?

[68fastback]

You may have a low pressure switch already if you have a pressure switch. You could have an electric contact switch instead. Some of the guys like manual brakes because the Cobras are usually overbraked and have no antilocks. It's harder to lock them up they say. You should have a pretty light steering feel as light as that Cobra is, somewhere around 2200 lbs I would think.

That's what many of my older vehicles had over the years had ...advantage is they activate immediately. Disadvantage is if the breake pedal gets 'sticky' and doesn't return fully you discover you have a dead batery in the morning. Some late 70s/early 80s Firebirds were famous for this ...two folsk I knew had them and both did this every now and then.

[Gr8snkbite]

You may have a low pressure switch already if you have a pressure switch. You could have an electric contact switch instead. Some of the guys like manual brakes because the Cobras are usually overbraked and have no antilocks. It's harder to lock them up they say. You should have a pretty light steering feel as light as that Cobra is, somewhere around 2200 lbs I would think.

true, steering is pretty light once you get rolling...i can handle it, LD will take some getting use to. It probably does have an elec switch. Still slowly going over all the wiring to see what is what, so i know...dont mind the braking so much, but stopping on a dime sure ain't happening....

[Gr8snkbite]

That's what many of my older vehicles had over the years had ...advantage is they activate immediately. Disadvantage is if the breake pedal gets 'sticky' and doesn't return fully you discover you have a dead batery in the morning. Some late 70s/early 80s Firebirds were famous for this ...two folsk I knew had them and both did this every now and then.

that explains why i needed a new battery....:banghead:


brakes return great, no binding, sticking , etc. at least from a light indication standpoint. I do have to flush the system tho, been three years, and i can see the e-brake sticking at the caliper when i apply it. had to use a screwdriver to release. Winter project to remove all brakes and do some TLC....:grin:

[Carnut]

true, steering is pretty light once you get rolling...i can handle it, LD will take some getting use to. It probably does have an elec switch. Still slowly going over all the wiring to see what is what, so i know...dont mind the braking so much, but stopping on a dime sure ain't happening....

Have you ever tried locking them up??

I know a lot of guys never get the poportioning valve set up or set up correctly. More than half of them I think.

[68fastback]

that explains why i needed a new battery....:banghead:


brakes return great, no binding, sticking , etc. at least from a light indication standpoint. I do have to flush the system tho, been three years, and i can see the e-brake sticking at the caliper when i apply it. had to use a screwdriver to release. Winter project to remove all brakes and do some TLC....:grin:

If you have the switch on the brake pedal (vs hydraulic switch) the brakes can be working fine but if the physical pedal doesn't return that last 1/16" at the top of it's travel (the pivot can get gunked up, etc) the tail lights can stay on ...or worse, go out and then -- hours later -- gravity or the slight pressure from the switch 'creeps' the pedal down a fraction of an inch and the lights come on (the old Firebird problem). I thought Carnut was thinking you have a hydraulic sw on the Cobra (and you may - dunno).

[Carnut]

If you have the switch on the brake pedal (vs hydraulic switch) the brakes can be working fine but if the physical pedal doesn't return that last 1/16" at the top of it's travel (the pivot can get gunked up, etc) the tail lights can stay on ...or worse, go out and then -- hours later -- gravity or the slight pressure from the switch 'creeps' the pedal down a fraction of an inch and the lights come on (the old Firebird problem). I thought Carnut was thinking you have a hydraulic sw on the Cobra (and you may - dunno).

The addition of a light return spring usually cures that problem.

[Gr8snkbite]

Have you ever tried locking them up??

I know a lot of guys never get the poportioning valve set up or set up correctly. More than half of them I think.

not yet, but that day will come in the spring...getting to cold now to play hard


If you have the switch on the brake pedal (vs hydraulic switch) the brakes can be working fine but if the physical pedal doesn't return that last 1/16" at the top of it's travel (the pivot can get gunked up, etc) the tail lights can stay on ...or worse, go out and then -- hours later -- gravity or the slight pressure from the switch 'creeps' the pedal down a fraction of an inch and the lights come on (the old Firebird problem). I thought Carnut was thinking you have a hydraulic sw on the Cobra (and you may - dunno).

not sure if the sw is hyd. still checking the system out. i do know most of the parts came from a 90 mustang

[Carnut]

1990 Mustang uses an electrical switch.

[The Bone]

I think my 68 uses a switch on the peddle because of the problems you are having. in most cars it's adjustable

[68fastback]

The addition of a light return spring usually cures that problem.

Wouldn't that make it press on the sw lighter? ...and not open the sw/ckt?

[Carnut]

Wouldn't that make it press on the sw lighter? ...and not open the sw/ckt?

This fix is where the brake pedal lays on a switch and runs down the battery, the spring would be intended to pull it up (off the switch), hence return spring.

[68fastback]

This fix is where the brake pedal lays on a switch and runs down the battery, the spring would be intended to pull it up (off the switch), hence return spring.

Ah ...ok, just the opposite then ...