Mechanical brake light switch

[wilsonmotors]

I am rebuilding my brakes. I have heard about all the issues with the brake light switch going out and leaking. I was thinking about the air switch upgrade but didn't like the idea that it might leak to and lose air pressure. So I was thinking about a mechanical switch for the truck. I found a small mechanical switch from a m998 that will plug right into my new harnes. I was wondering if anyone has done something like this or has any other ideas for this. I think that this would be a way safer upgrade has there would be no chance of any fluid or air leaks just a loss of brake lights if the switch went.

 

[frank8003]

Does your plan put the switch on the brake pedal itself or the linkage?

 

[Jeepsinker]

I have thought about it. I have the air switch and it doesn't leak but it takes a lot of pedal effort to get the brake lights to come on. Whatever you do, don't mount it to the pedal.

 

[wilsonmotors]

I was thinking about mounting a bracket close to the original position of the factory switch on the linkage.

 

[frank8003]

The cruise control and brake switch on most automobiles is on the pedal.
I am curious why "Not mount to the pedal"?

i.e. pedal moves+brake lights illuminate.

 

[Jeepsinker]

If he were to mount it to the pedal it would be dragging wires every time it moved. Most brake switches are not mounted to the pedal, they are mounted to a bracket by the pedal that allows the switch to decompress when the pedal moves away from it. Brake switches are normally open switches, that complete a circuit when the switch is released.

 

[Floridianson]

30 years for a switch to work and not leak a little is not that bad. Myself I would get a NOS pressure switch just like what was in there R&R and be done with it.

 

[Jeepsinker]

True enough, but in my case it would be nice to have a mechanical switch because I can actually come to a full stop at low speeds without ever having my brake lights come on. And I already installed a new pressure switch. No gunk or water in my lines. It just sucks.

 

[HanksDeuce]

For my hydroboost brake setup I installed a brake pressure switch in the Ford master cylinder (bottom) port. It's normally the port for the cruise control kill switch.

The switch is NAPA part number ECH SL147. It is pretty much the only pressure switch for newer style master cylinders that is compatible with Dot 5 brake fluid. I'm told this switch comes on at a lower pressure than most switches. The switch is male 1/8" NPT. I needed a female/male adapter from Speedway Motors to convert to 3/8-24" for the bottom port.

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Stoplight-Switch/_/R-ECHSL147_0475651800

Here's a link to Speedway Motors $7 universal mechanical brake light switch.

http://www.speedwaymotors.com/Universal-Mechanical-Brake-Light-Switch,1972.html

You could always run both switches in parallel. If the pressure switch craps out you have the mechanical as backup.

 

[rustystud]

Our busses us a 4 psi air switch for the brake lights. I bought one from a truck supplier for my rig. Now I'll just install it like the retrofit says and no problems !

 

[Jeepsinker]

Are the electrical connections the same, or is there splicing involved? You make it sound like it is plug and play... Please elaborate. Btw, I got a part number for that filter base today.

 

[rustystud]

Are the electrical connections the same, or is there splicing involved? You make it sound like it is plug and play... Please elaborate. Btw, I got a part number for that filter base today.

The pressure switch is a standard 1/8" NPT thread with 2 threaded studs to connect to. Great news about the filter base ! My friend quit working at IHC so I no longer have a inside man there anymore