Brake System light turned on.....
Thread Starter
1st Gear Member
Joined: Mar 2007
Posts: 104
Brake System light turned on.....
I am re doing my whole motor so after painted the engine bay and putting back the motor and putting back the brake booster and other brake wires... I started the car up and everything with went fine but my brake system light went on. So before disconnecting the brake booster and the lines there wasnt a light. So then i just bleed the brakes thinking it was that... so still got the air out of the brakes and the light wont turn off... i want to know if anyone else knows what i should try.... ive check the switch and i have power to it.... thanks for the help guys
1st Gear Member
Joined: May 2007
Posts: 134
From:
RE: Brake System light turned on.....
Hello.
There is a little piston inside the distribution block that indicates a pressure differential in the brake system between the front and back brakes. When you were doing your thing to the brakes, it drifted a little bit on you. Sometimes you can stomp on the brake pedal real harda couple of times and it will re-center itself. Hope that helps.
There is a little piston inside the distribution block that indicates a pressure differential in the brake system between the front and back brakes. When you were doing your thing to the brakes, it drifted a little bit on you. Sometimes you can stomp on the brake pedal real harda couple of times and it will re-center itself. Hope that helps.
Thread Starter
1st Gear Member
Joined: Mar 2007
Posts: 104
RE: Brake System light turned on.....
mmmmm well my switch is good.... it gots power going to it..... ill try what you told me.... so the little piston inside the distribution block is under the HOOD right.... ???
2nd Gear Member
Joined: Mar 2006
Posts: 490
From:
RE: Brake System light turned on.....
There is a diagram of the pressure differential valve at this site, along with a good brake basics article:
http://www.mustangmonthly.com/techar...ustang_brakes/
It is a common problem for the valve to move off center during bleeding or when there is a leak in the system. The article suggest that turning off the light, assuming the valve is in working order, requires a "differential bleeding process", but the technique is not explained. At some point in my youth, I read an article on differential bleeding, and I'll try to relay the process, but you decide if it makes sense.
1. If the switch is activated then equal pressure is restored to the system, there is nothing to cause the switch to move to the off position, so the light stays on.
2. Bleeding the systemmay or may notcause the switch to move to the onor off position.
3. If you have a tight system that is properly bled, the presense of the light doesn't indicate a current problem, hence the popular option of removing the connector from the switch to "silence" the light.
4. To get the switch to move, you must create a differential pressure across the switch.
a) turn on the key so you see the light is on
b) have a helper pump up the brakes and hold (like normal bleeding)
c) instruct the helper to tell you when the light goes off or when the pedal is about to hit the floor
d) with a 1/8" id tube on a bleeder and the other end of the tube in some brake fluid (to prevent sucking air into the system) crack open the bleeder valve
e) close the bleeded when the helper tells you
f) if the brake light went out, test drive the car, and once the driving is all done, share some beers with the helper.
g) if the brake light did not go out, repeat steps b, d, e, and fat the other end of the car (it doesn't matter if you do the front or rear of the car first)
h) if the brake light does not go out, repeat the bleeding process a couple of times to make sure you haven't screwed up something. If on any of these attempes the brake light goes out, repeat step f, otherwise your options are to R/R the differential pressure switch and completely bleed the system or go to your favorite classic mustang mechanic and apply $$$. You can jump straight to this step, but you would not have the self satisfaction of doing the job and your beer fund would take a hit.
Hope this helps.
http://www.mustangmonthly.com/techar...ustang_brakes/
It is a common problem for the valve to move off center during bleeding or when there is a leak in the system. The article suggest that turning off the light, assuming the valve is in working order, requires a "differential bleeding process", but the technique is not explained. At some point in my youth, I read an article on differential bleeding, and I'll try to relay the process, but you decide if it makes sense.
1. If the switch is activated then equal pressure is restored to the system, there is nothing to cause the switch to move to the off position, so the light stays on.
2. Bleeding the systemmay or may notcause the switch to move to the onor off position.
3. If you have a tight system that is properly bled, the presense of the light doesn't indicate a current problem, hence the popular option of removing the connector from the switch to "silence" the light.
4. To get the switch to move, you must create a differential pressure across the switch.
a) turn on the key so you see the light is on
b) have a helper pump up the brakes and hold (like normal bleeding)
c) instruct the helper to tell you when the light goes off or when the pedal is about to hit the floor
d) with a 1/8" id tube on a bleeder and the other end of the tube in some brake fluid (to prevent sucking air into the system) crack open the bleeder valve
e) close the bleeded when the helper tells you
f) if the brake light went out, test drive the car, and once the driving is all done, share some beers with the helper.
g) if the brake light did not go out, repeat steps b, d, e, and fat the other end of the car (it doesn't matter if you do the front or rear of the car first)
h) if the brake light does not go out, repeat the bleeding process a couple of times to make sure you haven't screwed up something. If on any of these attempes the brake light goes out, repeat step f, otherwise your options are to R/R the differential pressure switch and completely bleed the system or go to your favorite classic mustang mechanic and apply $$$. You can jump straight to this step, but you would not have the self satisfaction of doing the job and your beer fund would take a hit.
Hope this helps.
