Finally got all my wiring done, everything works [/u]except[u]...the brake lights won't shut off!
I looked and found that the brake arm that contacts the switch arm stops about 1/2" away from pushing the arm all the way up.
I temporarily fixed it by putting a rubber sleeve over the switch arm, several short lengths of hose glued together. That lets the brake arm move the switch arm enough to shut off the lights.
But I don't wee any way to adjust anything down there to fix it. Is there some way to move the switch, or adjust the arm to get it to work? If anyone has any ideas I'd be happy to hear them.
Tim
I am currently digging back in to a 1953 3800 (one ton) with a nine foot bed. I've owned it since 1979, and drove it until 1982 (or so). My wife got me involved in restoring it back in 2002, got the body removed and the frame redone, then things came up. Now I am retired and starting again. If anyone is interested I have photos on Imagur ( https://timwhiteblues.imgur.com/ ). I live way back in the woods in the Ozarks on 40 acres at the end of a 2 1/2 mile private road.
If you post a pic of two, someone may see what the problem is. Obviously something/part is not original or mounted correctly. AD folks will spot it. Otherwise they are guessing. Takes a lot longer sometimes. Get good light on the subject and post pics of on/off position.
Is it a new switch? What is stopping the brake arm? There is a toe board clearance adjustment per shop manual. Seems like the lower you mount the switch, the more the arm will trip it.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
The switch mounts in a fixed position on the bottom of the floorboard, so the brake pedal adjustment must be off. The service manual specifies that the pedal arm needs to be 13/16" from the bottom of the floorboard at the pedal opening. The master cylinder pushrod adjusts to get that to the right distance.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Thanks! I hadn't realized that adjusting the push rod changed the position of the brake pedal. I'll give that a try.
The switch is new from Jim Carter. And I replaced the original master cylinder with a dual master cylinder, also from Carter. I'll crawl under there tomorrow and see what I can do, then report back.
As far as I can tell, there is only one place to mount the switch, two holes in the toe board, no others nearby.
Tim
I am currently digging back in to a 1953 3800 (one ton) with a nine foot bed. I've owned it since 1979, and drove it until 1982 (or so). My wife got me involved in restoring it back in 2002, got the body removed and the frame redone, then things came up. Now I am retired and starting again. If anyone is interested I have photos on Imagur ( https://timwhiteblues.imgur.com/ ). I live way back in the woods in the Ozarks on 40 acres at the end of a 2 1/2 mile private road.
I've been told it was fairly common back then to just slip a piece of heater hose over the switch arm instead of crawling under the vehicle to adjust the brake pedal. I've retrofitted my '38 to a lever operated manual switch and had to do that to get the clearance right.
Save a life, adopt a senior shelter pet. The three main causes of blindness: Cataracts, Politics, Religion. Name your dog Naked so you can walk Naked in the park.
I had the exact same issue with my brake light switch, and tried to fix it with hose until I realized all I needed was to adjust the master cylinder push rod. Doesn't need to be turned much to move the pedal are quite a bit to the 13/16 spec toe-board clearance. Of course I had bought a new switch in the process, and now I have 2.
Last edited by 4100 Fire Truck; 03/24/201912:24 PM.
I went out this morning and crawled under the truck and found the adjusting nut, turned it about 1/2" longer, and it made no difference in the position of the brake arm. It seemed that all it was doing was pushing the rod in farther. I removed the pedal from the brake arm, in case that was somehow binding and interfering with movement, and it made no difference.
What I finally ended up doing was to pull the brake switch and weld a steel plate onto the arm, adding about 1/2 " to it on the dege that contacts the brake arm. That solved the problem, now my brake lights go on when I step on the pedal, and off when I release.
I'm wondering if the fact that I have a dual master cylinder rather than an original makes any difference. Could it be that the adjustment is different? Don't know what's going on, but at least my lights are working right.
Tim
I am currently digging back in to a 1953 3800 (one ton) with a nine foot bed. I've owned it since 1979, and drove it until 1982 (or so). My wife got me involved in restoring it back in 2002, got the body removed and the frame redone, then things came up. Now I am retired and starting again. If anyone is interested I have photos on Imagur ( https://timwhiteblues.imgur.com/ ). I live way back in the woods in the Ozarks on 40 acres at the end of a 2 1/2 mile private road.
Isn't there a pressure activated brake light switch that can be plumbed into the brake line just behind the master cylinder that eliminates the arm type switch?
Isn't there a pressure activated brake light switch that can be plumbed into the brake line just behind the master cylinder that eliminates the arm type switch?
You could definitely do that with a modern pressure switch. F250's with factory cruise use one on the nose of the master cylinder to disable cruise when the brakes pedal is pushed. It's a redundant switch. The mechanical one on the brake pedal activates the brake lights.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I have had less than satisfying results with replacement pressure switches on these older vehicles. The big variable is the pressure required to activate the switch. And it is hard to find that data.
You want to get as low a pressure switch as possible because these brake systems operate at lower pressures than late 50's and 60's vehicles. A 100 psi switch (common on Fords) will not turn the lights on until you are well into the brakes on a '30's or '40's Chevy.
I finally found a NOS GM switch. It is a 30 psi switch so works much better. I am still going to go the same thing Tiny did and add a mechanical switch to my '37.
