• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Brake question

Share this page

JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Online
In another thread, Bill just wrote

"Your red brake check light should come on with your emergency brakes, or if the brake balance switch trips; i.e., if you lose either your front or back brakes. The earlier brake check lights would be built into a push-switch to test it. (Most of them have stopped working long ago.)"

Bill, my brake check light is staying on - yet all is new, what should I check? and how?

switch?

brakes?

help?

thanks
 
1. Remove light cover.
2. Unscrew light.
3. Replace cover.
Voila! :banana:

Seriously, though, there's only a few points that can be sticking. Since I <span style="font-style: italic">know </span>you have everything wired right, we can rule that out. :wink: Start with the e-brake switch, and make sure the plunger isn't stuck. Since you have a '76 warning light, it <span style="font-style: italic">shouldn't </span>have the pushbutton, so that can't be the problem. (check anyway just to be sure--)

The proportion valve works by providing a ground path for the light. Inside it, a little barbell-shaped shuttle moves back and forth. When one end of the barbell touches the switch contact, it grounds and the light comes on. Both wires to the switch are grounds, as I remember, and the shuttle connects the two, and grounds through the valve as well. As long as the front and rear pressure are the same, the shuttle doesn't move. If one side loses pressure, the pressure on the other side moves the shuttle over. I recall that the position of those two ground wires is important: if they are reversed, the light grounds through the valve all the time.

Sometimes when you're bleeding your brakes, the pressure difference will pop the shuttle to one side and trip the switch. You'd need to center the shuttle again, by cracking a bleeder on the far side slightly while pushing the brake pedal. If you bleed back-to-front, try a final little bleed on a rear wheel. I bet that does it!
 
Thanks Bill, before I do something unnecessary, I don't have the e-brake switch hooked up at all - though I plan to - would this make a difference.

I wouldn't stake my life on the wiring being correct, but I'm pretty sure.

My anxiety is that the only thing I didn't pull apart was the proportion valve - didn't realize till too late that there was something to pull apart. Though it should be good.

If it is bleeding, I may wait till a friend is over, but will check - cheers!
 
Yesterday my brake warning light came on while I was out for a drive. I pulled over and did an inspection of everything. Couldnt find a thing wrong. Brakes worked fine. Then I noticed I bumped the emergency brake handle just a enough for the light to come on. I "barely" moved it out of its neutral position and that light came on. Which makes me wonder if your emergency brake arm is allowed to go down all the way or if that switch needs adjusted just a bit.
 
If you have not checked out the new Moss TV videos check them out they are quite informative. They have one about brakes and it describes the bar bell plunger and how it operates and how to properly bleed.

Mark
 
Back
Top