brakes


The old and reliable.

Rookie
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Joined: Tue Mar 27, 2018 1:47 am

Post Sun Jul 22, 2018 7:53 am

brakes

need help, my brake lights stopped working(49KB2). After doing some investigating I think I have it narrowed down to the stop lamp switch on the end of the master cylinder. If I jump from the "hot" post to the other post the lights come on but it does not work when stomping on the pedal. I had a few of these switches in a box(one was brand new) and tried each of them and it still does not work. I assume these work on pressure so I checked each one by screwing them onto the end of a air blow gun and firing up the air compressor. Using my meter I see an indication of continuity when turning air on so I assume these switches are good. Could there be an issue with the master cylinder? I have good brakes and brake fluid leaked out when I took switches out so I am guessing there is nothing plugging it up. Getting frustrated...

Golden Jubilee
Golden Jubilee

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Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Sun Jul 22, 2018 12:59 pm

Re: brakes

If the brakes have enough pressure to slow or stop the truck and you do not see any leaking, I would presume that the master cylinder is working. These POS pressure switches were never any good and they were subject to nearly a 100% failure rate in a very short time. I never ever used these pressure switches on any of my Old IHC pickups. I opted to design a bracket to hold a small press-button switch. This switch style has three poles and they are marked common, normally open and normally closed. You will want to have the switch in the open position when the brake pedal is fully up. Once the brake pedal is activated, the switch will move to closed and complete the circuit.
I am going to include a picture of the switch bracket I made for my 1940 Ford. These old vehicles have more in common than what many persons think. The Ford is using a BOSCH brake booster and the master cylinder is Ford Explorer 4 wheel disc unit. There was not an option for a POS pressure switch.
The Ford trucks of the 1990s had an ingenious brake switch that mounted in the brake linkage at the pin to pushrod to the master cylinder. I am including a picture of the switch on the off-chance you or anyone may be able to figure it out and use it. I used the Ford brake light switch on my R120 for 225,000 miles and two decades.
The threaded opening in the master cylinder for the pressure switch can be plugged with an 1/8" pipe plug.
Attachments
FORD F BRAKE SWITCH.jpg
new brake switch 3.jpg
new brake switch 2.jpg
new brake switch 1.jpg
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Yard Art
Yard Art

Posts: 62

Joined: Wed Aug 02, 2017 11:17 am

Post Mon Jul 23, 2018 9:42 am

Re: brakes

I did a fab job similar to Nikki's on my KB-7. Used a GM push button style and fabricated a bracket out of uni-strut on the brake pedal assembly near the pivot point.

Golden Jubilee
Golden Jubilee

Posts: 8937

Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Mon Jul 23, 2018 10:35 am

Re: brakes

That is another great idea.
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Rusty Driver
Rusty Driver

Posts: 110

Joined: Mon Dec 03, 2012 9:39 am

Post Mon Jul 23, 2018 10:30 pm

Re: brakes

Doesn't seem too original to me. This discussion belongs in the "modified" category or maybe the "'84 and newer Ford F250 Forum".


Bud
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Golden Jubilee
Golden Jubilee

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Location: Bothell, Washington

Post Tue Jul 24, 2018 1:57 pm

Re: brakes

low pressure ones on ePay, look exactly the same activate a lot easier
Gentle Men! you can't fight in here! This is the war room!

Golden Jubilee
Golden Jubilee

Posts: 8937

Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Tue Jul 24, 2018 3:37 pm

Re: brakes

buddawson wrote:Doesn't seem too original to me. This discussion belongs in the "modified" category or maybe the "'84 and newer Ford F250 Forum".


Bud

Is this the best comment you have.
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Rusty Driver
Rusty Driver

Posts: 110

Joined: Mon Dec 03, 2012 9:39 am

Post Tue Jul 24, 2018 10:42 pm

Re: brakes

This if for nikkinutshop:

Maybe a further comment. If you put the new deal through an onboard computer (obc) then give it a diagnostic code (obd) . Then get an expensive obd code reader from NAPA. Then get a code number: Next you go to the incredible OHC.ORG forums to help you solve the problem. What was the problem? brake lights "working" or "not working" and think of the fun giving it a code number!!!

Gone full circle, eh.

Bud

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Post Fri Jul 27, 2018 3:50 am

Re: brakes

I actually was thinking the same thing and bought a push button switch to rig up. I too struggled with losing the originality of the truck (only thing "new" is electronic ignition) so I took a deep breath and took another look at it. As you all know the pressure switch has 2 posts on it, I switched the wires on the posts of the new switch I put in and wouldn't you know, the lights worked. It did not occur to me that that would make a difference. :t0174: I never claimed to be a genius and I have proven it once again. Thank you all for the advice.
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Golden Jubilee
Golden Jubilee

Posts: 4922

Joined: Thu Nov 29, 2012 11:47 am

Location: Bothell, Washington

Post Fri Jul 27, 2018 10:35 am

Re: brakes

Wow, didn't think that pressure switch had a directional preference
Gentle Men! you can't fight in here! This is the war room!
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