I got my new rear disc brakes installed and adjusted and they work nice now. Now I'm having difficulty with the brake light coming on. I have a pressure type switch in the brake line. The brake lights come on, but I need put more force on the pedal creating more pressure in the lines with the disc brakes. I was told they sell a switch which comes on with less pressure or the best route is to use a mechanical switch. I haven't got a clue what type of hanging pedal I have but could use some suggestions on ways of using a mechanical switch versus using the pressure type brake switches. I'm looking for ease of installation here, for some reason, my brake projects take too much of my time. Here's a pic of my hanging pedal.

 

there are a number of mechanical switches.. some mount to the firewall, and have a longish arm that rest against the brake pedal arm and turn the lights on with the press on the arm.. Some go the opposite way, fit on the uphill side and connect when the arm pulls away from the switch..
I am going to use the latter, from a mid 70s ford truck, on my 55..
I will have to fashion a bracket to hold it against the pedal arm..

Watson Streetworks has a good switch. This is the firewall mount type

Sam

 

Ed, I personally would use a mechanical switch mounted off the bracket next to the brake swing pedel. The momentary/brake switch from most GM and Ford are adjustable so if you could get an "L" bracket and mount so on/off movement could be fine-tuned. At least thats what I'd do. Good luck in your endevors. Kurt G. Y-blocks rule.

 

Ed, I am interested in your experience with the pressure switch since that has been the route that I planned to take. Do I understand it correctly that the pressure switch worked ok with the disc/drum setup but not with 4 discs? I am using a stock position thru the floor brake pedal on my 49 with a changeover to power brakes. I did not see a clean way to use a mechanical sdwitch so I am interested in your and others experience with a pressure style switch with a disc/drum setup. Since I am also setting willard up to tow heavy (5000#) with electric trailer brakes and an older style mechanical/ cruise control, I would be concerned if there was a significant delay in pulling in the stop lights with a pressure switch. Your thoughts? Anyone else?

 

One would think that any of the pressure switches off a late model vehicle w/4w disk would work well. Just tour the salvage yards to find one that has the same thread, and screw her in. Might want to grab the electrical connector for it also.

 

Bill, that is exactly correct. My switch and brake lights worked nicely with the disc drum setup, however with the disc in the rear, it changed the pressure within the lines being that disc take more volume or pressure. Now, I'm not sure if it is more pressure to apply the brakes or less? I do know that if I apply more pressure to the brake pedal (which means more pressure) my brakes will come on which tells me there needs to be more pressure in the line for the switch to activate. I know MF sells a hydraulic brake switch that is low pressure meaning it comes on at 20-60 lbs of force vs. the standard switches that require 90 and more pressure. I could try the low pressure switch which would probably solve my problem, however I'm opting for the mechanical switch which works regardless and appears to be simple. I've read that the hydraulic switches are known to go faulty after 4 years or so. That's why I'm considering the mechanical one and be done with it. I have a 66 Mustang which has the mechanical switch. It appears that it simply slides on the hanging pedal where the mastercylinder arm connects. That might an easy way! With your MC on the frame, I see your delemma. I know they have switches for that setup also. See Seidweil's post above. The website he posted show the setup you need for the floor mounted version. I'm not sure the best way to go right now. Waiting for some FTE ideas to generate. LOL.

 

Go for the mechanical; can't get more simple that that, and it works!

 

You could use a rear brake light swich from a motor cycle. a simple l bracket with a hole for the switch to go into an a small spring to the pedal arm. it is very easy and quite cheap,about $15 for switch and sping from bikebandit.com I have used switch from 1974 XL 250 honda for brakes and door release selonoids.

 

I got my mechanical switch from Autozone for about $7..

just have to make that L bracket yet..

Sam

 

I had a few brake light switches laying around from a Ford Mustang. I thought that would work nicely, but the hole diameter on the shaft that the MC arm connects to is much smaller than that of the switch, therefore that won't work. Would of been an easy set up. Back to the drawing board!

 

Mecanical switch for sure.Be aware there are two types of switches -one for vehicles with cruise control and ones without c. c. two different switches. Mark

 

"Overkill" posted on another forum recently that the Harley Davidson motorcyle pressure switch is low pressure, and someone used it on their truck -- BUT it was not a disc system, as I recall. Not clear that it would hold up to really high line pressure like a disc/disc system. There've been a lot of posts lately about crappy replacement pressure switches, any chance you just have a cheap/bad one?

 

Ross, could very well be... The reason I posted this subject was that I want to replace the hydraulic switch and go with a mechanical switch which is less problematic than the hydraulic units. I'm trying to get some ideas from those guys who have changed over to the mechanical. What switch are they using? How does it work? and what they did to make the switch work. I've been doing searches on the subject and coming up with nothing? I figure there has to be more people out there who have gotten rid of the hydraulic and went mechanical? I've checked just about every Hot rod site and forum I can think of and nothing out there. Maybe I'm wrong? I do agree with you on the low pressure ones, what's to say the disc/ disc system doesn't blow them out! Good point! Another reason I want to go with mechanical.

 

I tried a pressure sensitive switch plumbed into my brake line, and it didn't work well. I tried two different ones and neither worked that great. I then went to NAPA and got a plunger/mechanical style brake switch for a mid to late 70's Ford pickup. I made my own bracket for it so it made contact with the brake pedal and mounted it off of the frame. Very easy, very simple, and the switch was fairly inexpensive.

 

Thanks Brandon, that's what I'm looking for. Does that switch mount on the outside of the pedal arm (plunger extends turning on the lights) or does the pedal push down on the plunger turning the brakes lights on. Any pics on the install? Thanks. may have to see Napa tomorrow... Is this what it looks like?