79 Transporter - brake lights work only under hard braking

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airkooledchris
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79 Transporter - brake lights work only under hard braking

Post by airkooledchris » Wed Jan 15, 2014 10:39 am

Ive got this on both of my buses currently, where if I use anything less than half of the available pedal pressure on the brakes - the lights won't come on.

Is this a side effect of worn switches on the master cylinder?

I knew it was happening on one of the buses, but someone pulled up beside me the other day in my primary bus and said my brake lights were out. They weren't, but I hadn't needed to depress the pedal far enough for them to come on either.
1979 California Transporter

bajaman72
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Re: 79 Transporter - brake lights work only under hard braki

Post by bajaman72 » Wed Jan 15, 2014 3:04 pm

My buddy has a squareback that does the same thing. I beleive it is from the front switch being bad and only the rear one is working. I have not been able to confirm this because he doesn't really care if they work or not. :pale:
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Amskeptic
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Re: 79 Transporter - brake lights work only under hard braki

Post by Amskeptic » Wed Jan 15, 2014 9:05 pm

airkooledchris wrote:Ive got this on both of my buses currently, where if I use anything less than half of the available pedal pressure on the brakes - the lights won't come on.

Is this a side effect of worn switches on the master cylinder?

I knew it was happening on one of the buses, but someone pulled up beside me the other day in my primary bus and said my brake lights were out. They weren't, but I hadn't needed to depress the pedal far enough for them to come on either.
Plural of bus is many "buses". Thank the British for all of these weird rules.

I would install new (quality German) switches and see if they work with greater sensitivity. Although I am intrigued by bajaman72's explanation, I don't know how that would affect switch pressure.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

kreemoweet
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Re: 79 Transporter - brake lights work only under hard braki

Post by kreemoweet » Wed Jan 15, 2014 9:59 pm

This is typical of low-quality brake light switches. It's the reason I converted to a mechanical switch long ago: the only stock-type switches I could obtain at the time
either failed in the manner described within weeks, or were bad right out of the box. The switches work independently, and one switch being bad will not affect
the function of the other.

The contacts inside the switch might arc excessively and wear or become fouled if they are made to carry greater current than they were designed for, as happens when
people install "third" brake lights. In such a case, using a relay to operate the brake lights would be the thing to do.

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airkooledchris
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Re: 79 Transporter - brake lights work only under hard braki

Post by airkooledchris » Thu Jan 16, 2014 11:17 am

Thanks for the replies. Im going to try two new German made ATE brake light switches to see if this helps first.

I think, in part, that the problem was made worse by my last brake adjustment, as I require a lot less pedal now than I did before to get the stopping power I need. They aren't dragging - just adjusted to where I have pedal right away now. It only takes me 4 clicks out on the e-brake to get full lock.
1979 California Transporter

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Amskeptic
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Re: 79 Transporter - brake lights work only under hard braki

Post by Amskeptic » Thu Jan 16, 2014 2:53 pm

airkooledchris wrote: I think, in part, that the problem was made worse by my last brake adjustment, as I require a lot less pedal now
Pressure actuated switches should not care in the slightest. They are reading only the shoes/pads once they have arrived at the drum/rotors . . . . I maintain my brakes at top of the pedal and have not had any noticeable light actuation issues.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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airkooledchris
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Re: 79 Transporter - brake lights work only under hard braking

Post by airkooledchris » Sat Feb 06, 2016 8:50 pm

bad bus owner confession:

I still have those two new german switches sitting in a box in the garage and the brake lights still don't come on without excessive pressure.

I'm an ass and will TRY to get to this job this upcoming week.

Doh.
1979 California Transporter

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Re: 79 Transporter - brake lights work only under hard braking

Post by Amskeptic » Sun Feb 07, 2016 8:08 pm

airkooledchris wrote:bad bus owner confession:

I still have those two new german switches sitting in a box in the garage
Let us know if the required pedal effort to turn on the brake lights goes down,
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

cegammel
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Re: 79 Transporter - brake lights work only under hard braking

Post by cegammel » Wed Feb 17, 2016 3:08 pm

I have the same issue in my vanagon. I tried new switches last year, with no change...

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airkooledchris
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Re: 79 Transporter - brake lights work only under hard braking

Post by airkooledchris » Wed Feb 17, 2016 3:17 pm

Mine seems to have worked, brand new German made switches. Need to test again now that some time had passed
1979 California Transporter

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hercdriver
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Re: 79 Transporter - brake lights work only under hard braking

Post by hercdriver » Thu Feb 18, 2016 6:42 am

airkooledchris wrote: brand new German made switches.
From who did you buy those switches? Link?
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