I have my brakes all the way backed off. I drove my truck tonight, when I parked it the brake lights stayed on. It seems as if the master cylinder or the booster is not releasing. What can cause this? I thought I had the brakes adjusted to tight, but not now as I had them all the way backed off. Any advice? I need to fix them tomorrow.

Thanks Kevin

 

Is this a pressure switch that is plumbed into the brake lines? or is this a plunger style switch that comes on when the brake pedal is pressed?

I had the same problem with a switch that was plumbed into the brake lines. I could never get it to work right. I even went with a low pressure sensing switch and that didn't work either. My brakes would come on and not go off just from the weight of the pedal when I had it parked. When I would have the engine running and was driving it, the brake lights would sometimes stay on all the time or not come on at all. It was really weird. I had the same problem with two different "switches".

I finally had enough of that and installed a pedal return spring thinking that might help, it did not. So, I said forget this whole pressure switch deal. I went to NAPA and bought a plunger style brake switch for a mid 70's ford F-series. Went home, made a bracket to mount the switch so it would sense movement and activate the brake lights. This setup has worked perfect ever since. I know some guys have had luck with the pressure switch, but I have had none and my brakes work fine. Just my experience.

 

Kevin, the parts catalog shows only one type of stop light switch for your application. This is the pressure type that screws into either the master or a brass block somewhere in the system, and has two male ends for the wires to attach. My question to you is, did you replace the old one? If you did, have you since bled the brakes?


What happens many times is the switches get plugged up with old thick brake fluid, or by some foreign object. Try replacing the switch. Ford used this same switch on cars and trucks through 1967.


C1AZ-13480-A .. Brake Light Switch (Motorcraft SW-24)



If walford shows up at your place driving his Avanti, steal the switch off that..it's the same one..Studebaker p/n: 666858

 

Kevin, do you have the "hydrovac" system. Do you have the shop manual for 51's. If so, there's a atmospheric filter that could be clogged. If you don't have the manual, call me.Jim

 

Do you have LED tail light bulbs? I put them on mine, with 10 lb risidual valves in the brake lines, and apparantly the residual pressure was enough to cause the switch to just barely send a current to the LEDs and they glowed faintly all the time. Put regular bulbs back in and the problem went away. Did not find this until I was installing a cruise control and it wouldn't work, finally figured out when I was splicing into the brake light wire after the switch it was enough to make the cruise module think the brakes were on.

 

There is a push rod that goes into the master cylinder that is adjustable. Back it off a few turns and you'll be OK

Kevin Bigwin

 

Thanks bigwin. I am going to do both replace the switch and back off the push rod.

I could not get on today until now.

 

Problem solved!1 That was all that it needed was the adjustment. I put the switch on as well seeing as though it was only $9.00. Trailer is supposed to be on its way. Thanks Bigwinf100 and number dummy for the help.

 

Don't listen to number dummy--you ain't gittin' my Avanti parts,Kevin!!!!hahaha--I am packin' and leavin' Thursday after 12-if wife get's here--she just got a new job as Supervisor and thinks I have to listen to her,now--although with more money-I can buy more trucks!!!!COOL!!!!!!

 

She told me you had to finish the avanti first. No more trucks before the Avanti. Finish hers then get more for you. We are leaving at 12.30 just talked to Andrew and Jim Hackney. Julie is supposed to get out of work with enough time, so we will se. I have two leads on trailers, neither one has come through yet. I will rent one if I have to. I want my truck there.

 

Have a great trip,Ohio convoy!!!!I am sorry to miss it--but if there is trouble-I will be right behind you Thursday. Avanti---is done--just need to put in radiator and carb back on--tried to tell her nothing else needs done!!!!!See you guys Fri/Sat/Sunday.

 

Glad to hear you got it figured out.