Brake light on dash after converting to

87lc2/wo2

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Joined
Nov 25, 2007
Vacuum brakes. I had the pedal changed, added a dual diaphragm brake booster, a vacuum block with a orifice for the new booster and a new master cylinder. I then bled the brakes. Now, the brake light on the dash stays on. I'm assuming that I have to remove the Hydroboost brake fuse on the fuse block. Is this correct? Which fuse is it, because I don't have an owner's manual for my '87 Turbo T.
 
When the brake light on the dash is on, it usually indicates there is still air in the system.
 
Or the emergency brake got pressed a bit when working on the install like mine did. :p

Check your pedal. :smile:
 
There's only 3 things that turn on the brake lamp on the dash:

E brake switch

Low psi switch on the powermaster

Proportioning valve switch



Since you said the car has a vac conversion that really only leaves 2 switches to cause it to come on.
 
I would assume your light will always be on due to the fact you removed the power master system. just remove the light in the dash its very simple. remember you removed the factory system and converted to a different style. Your light would always be on I would guess. also check the wire to the brake valve on the frame as well not sure if it will cause the light to come on but check it anyhow.
 
It's also possible the plug for the powermaster brake switch, that the pin for turning on the lamp somehow became grounded.
 
I would assume your light will always be on due to the fact you removed the power master system. just remove the light in the dash its very simple. remember you removed the factory system and converted to a different style. Your light would always be on I would guess. also check the wire to the brake valve on the frame as well not sure if it will cause the light to come on but check it anyhow.

wrong

removing the pm doesnt cause a brake lamp to light
leave the light in the dash... its there to warn you of a problem ,

if you want to know if its the prop valve showing a brake imbalance just unplug it and if light goes out you know youve got air or a leak somewhere
normally just swapping a master doesnt require a full bleed as long as you bench bled the master off the car, its an important step that can't be skipped

the other switch that can cause the brake light is above and rear of the ebrake assembly under the dash
 
After bleeding the entire system, the dash brake light turned off. I didn't remove a bulb or fuse. I appreciate everyones reply.
 
i think i need to bleed mine again after my vacuum conversion, cause mine suck even after new rotors and calipers the fronts wont hold while trying to build boost.
 
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