PA Jeeps
The Garage => Technical Advice and Questions => Topic started by: j.haffly on April 03, 2013, 07:32:58 am
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I replaced my rear wheel cylinder, not problems actually....BUT....how do I get the brake light itself to turn off?!?!??!
Jim
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I'm thinking the switch at the pedal is stuck.....
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I think you're right Jim. They are plastic and prone to wear. A simple plastic cylinder with a spring that the pedal depressed. Replace it.
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I think you're right Jim. They are plastic and prone to wear. A simple plastic cylinder with a spring that the pedal depressed. Replace it.
Ok...going stupid here....I've disconnected the electrical connector to the brake light switch but cannot seem to get the switch itself off....is there any kind of 'trick' to removing it? Also, the brake light has remained on with the switch disconnected, is that correct?
It's a 1997 TJ....
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yes its a reverse pressure switch. im not sure but most of them are threaded.
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yes its a reverse pressure switch. im not sure but most of them are threaded.
Not sure I'm following....I assume you are talking about the 'plunger' that is threaded....it seems to be working with no issues....the light itself came on when the wheel cylinder finally completely failed before I replaced it....it's been on since then....
There's an electrical connection which I've removed...however, the 'box' that is now unplugged is still attached to the brake pedal....are you saying that that assembly is a screw-on?
Jim
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yes the brake pedal switch ,little plastic thingy behind brake pedal, the metal bracket it is connected to. the hole in the bracket is threaded and the switch itself turns. that's also how you get your correct distance adjustment for the brake pedal.
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Any luck on this? the brakes lights have nothing to do with your actual brakes. the lights don't care if you have brakes. they only care about the brake pedal position. when brake pedal is released the switch is pressed in which opens the circuit removing power to the brake lights. when you press the pedal the switch is relaxed closing the circuit allowing power to illuminate the lights.
Are all the brakes lights on or just one? if just one then there is a issue just at that light. maybe an electrical short.
Also when you disconnected the brake light pedal switch (if it is the right one) the lights should not be on. with the plug disconnected there is no way for power to go thru the switch to turn on the lights.
i dont know if it matters or even applies to you but some cars with cruise have a second switch on the brake pedal arm just for the cruise cancelling.
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Any luck on this? the brakes lights have nothing to do with your actual brakes. the lights don't care if you have brakes. they only care about the brake pedal position. when brake pedal is released the switch is pressed in which opens the circuit removing power to the brake lights. when you press the pedal the switch is relaxed closing the circuit allowing power to illuminate the lights.
Are all the brakes lights on or just one? if just one then there is a issue just at that light. maybe an electrical short.
Also when you disconnected the brake light pedal switch (if it is the right one) the lights should not be on. with the plug disconnected there is no way for power to go thru the switch to turn on the lights.
i dont know if it matters or even applies to you but some cars with cruise have a second switch on the brake pedal arm just for the cruise cancelling.
It's not the brake lights themselves....it's the brake light on the dash giving me the issue....cant get it to turn off no matter what I try....
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ok so that has nothing to do with the brake pedal switch. that switch is only for the lights and possibly the cruise. Is it the "brake" light on the dash or the "ABS" light?
If it is the "brake" light then the issue is with the emergency brake. i have never had to mess with it but i would assume there is a switch on the lever under the center console. it would be possible for this switch to be bad or a electrical short. it might also be a rigging issue. If you have messed with the emergency brake cable it might be adjusted too tight preventing the brake from releasing all the way. Not sure if that would cause the issue or not. As i said i have not had to mess with it before.
If it is the "ABS" light then it would be either a bad sensor at one of the wheels. each wheel has its own pulse sensor which measures wheel speed. Or it could be the computer or the ABS brake manifold under the hood. First thing to do would be to find an empty parking lot or more preferably a dirt road and see if the ABS is working. If it is working than the issue is probably a bad sensor. Also you can connect a OBDII scanner up to read the codes for the ABS system.
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the brake light on the dash also refers to the electrical plug on the master cylinder,( if you have one), and also the electrical connecter on the brake proportioning valve. it could be the prop valve is bad or a connection came loose. I unhooked it once replacing a brake line and forgot to hook it back up took me 2 weeks to figure it out.
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Thanks guys!!! Good stuff....the light came one when I started having the wheel cylinder issue so I replaced that of course but the dash light never went out....will check at the master cylinder and the E-brake lever....
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Ok...pulled the electrical connection at the master cylinder....no more dash light!!!! Now to figure out what is exactly wrong....
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The wire to the combination or proportioning valve detects a shift of the piston caused by a
significant difference in pressure between the front and rear circuits
If you get a little too aggressive with the brake pedal when bleeding the brakes, the valve sees
this as a brake line failure and the piston shifts to shut of that circuit.
That way you would still have good enough brakes to get to a stop.
The only way I know to get the piston back in place is to remove the switch
and pry the piston back into center.
You can confirm that is the problem by checking to see if your rear brakes are working correctly.
I am not sure this is your problem but it reminds me of what I went through some years ago.
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Not sure if that's it or not....but will have to look at the possibility....all the brakes seem to be working with no real issues....
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A way to check is to remove the plug from the combination valve and see if the light goes off.
If it goes off, then the piston in the valve has shifted.