Scarry Brake Light Switch Failure
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How many pins in the super duty switch? Did you use just two? What year is the switch from? Per my 1984 factory manual all platforms use the same switch, 13480.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum. That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum. That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
Fleet Mechanic
Joined: Aug 2011
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How many pins in the super duty switch? Did you use just two? What year is the switch from? Per my 1984 factory manual all platforms use the same switch, 13480.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum. That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum. That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
Tie pin 3 and 5 together, tie pin 2 and 4 together and ground pin 1 (or leave it alone if you don't want to overly modify things)
Pin 3+5 hook up to your green with red wire and pin 2+4 hook up to the green brake wire and pin 1 to a good dash ground.
Fleet Mechanic
Joined: Aug 2011
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I did it to run led brake lights without the load resistors.
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I finally got a few hours to get back to this brake light switch problem.
The first thing I did was bend the plate where the spring plunger touches on the switch. This causes the switch to close sooner. This eliminated the scary cruse control problem. I can do a proper tap to disengage now.
As seen in the test light, the switch is not quite right yet because the contacts "bounce" (the lights flicker) under light braking.
What I need to do is have more pedal travel before the piston in the master cylinder starts to move. A quarter inch should be enough.
Is the rod between the brake pedal and booster adjustable for length?
Thanks
The first thing I did was bend the plate where the spring plunger touches on the switch. This causes the switch to close sooner. This eliminated the scary cruse control problem. I can do a proper tap to disengage now.
As seen in the test light, the switch is not quite right yet because the contacts "bounce" (the lights flicker) under light braking.
What I need to do is have more pedal travel before the piston in the master cylinder starts to move. A quarter inch should be enough.
Is the rod between the brake pedal and booster adjustable for length?
Thanks
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It looks like I would have to remove the master cylinder then the booster to get to the rod for adjustment. I don't know if shortening the rod would even help with the brake light switch problem.
Any opinions?
Any opinions?
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Whoo Hoo!! Finally got it working right!
I disassembled the switch and replaced the spring with a much lighter one.
Now I can do a proper tap to release the cruse control. And no flickering. As long there is light pressure on the pedal the brake lights will stay on.
It is almost too sensitive now. I will try a heaver spring and see if it feels better.
This is a fix that anyone can do on the bench in about 15 minutes after the correct spring is sourced.
The test light that is needed to see if your brake light switch is working properly while driving can be made in about the same amount of time once the parts are in hand.
I disassembled the switch and replaced the spring with a much lighter one.
Now I can do a proper tap to release the cruse control. And no flickering. As long there is light pressure on the pedal the brake lights will stay on.
It is almost too sensitive now. I will try a heaver spring and see if it feels better.
This is a fix that anyone can do on the bench in about 15 minutes after the correct spring is sourced.
The test light that is needed to see if your brake light switch is working properly while driving can be made in about the same amount of time once the parts are in hand.
Hotshot
Joined: Jun 2015
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How many pins in the super duty switch? Did you use just two? What year is the switch from? Per my 1984 factory manual all platforms use the same switch, 13480.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum.That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
I pressure blead the wheel cylinders, RABS module and front calipers. They are hard as a rock with the vacuum drained but mushy with vacuum.That is normal, right?
The drums (NOS) and shoes are new and were adjusted to a light drag about 100 miles ago.
New Old Stock drums?? Kinda hard to believe a dealer had brake drums sitting around for all these years.
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Give me a few days to go to the hard ware store to find one similar and I'll post the size and part number.
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Mushy is not normal. It’s a Ford not a Chevy. It should be firm but not hard like when there is no vacuum in the system. I think you made a mod to the system that didn’t really address the underlying issue.
New Old Stock drums?? Kinda hard to believe a dealer had brake drums sitting around for all these years.
A mod? Are you talking about the lighter spring in the brake light switch? I am open to suggestions to identify the underlying issue and at least one other person is too.
Got them on eBay. The dealer was able to get drums in a box with a Ford logo and part number but they were the same crap that everyone else were pushing at twice the cost.