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Parking Brake light stays lighted

PostPosted: 09 Jan 2012, 15:40
by JMK3521
This could be an electrial problem or brake problem... I'm wondering if it could either be the parking prake needs and adjustment, or maybe the sensor that comes off the parking brake that powers the light could be bad? if any one has any suggestions or ideas please let me know.

Re: Parking Brake light stays lighted

PostPosted: 09 Jan 2012, 16:26
by SUPERMOD
My arty mech friend says try bleeding the brakes. If there is air in the system the brake light can stay on. Shot in the dark.

Re: Parking Brake light stays lighted

PostPosted: 13 Jan 2012, 10:05
by MarineOL3529
Most often than not if there is no air in the system and the switch next to the Master Cylinder is functioning properly the PCB is the issue, I am not usualy one to throw parts on a problem but if you have a spare PCB try changing it out to see if this corrects the problem.

Re: Parking Brake light stays lighted

PostPosted: 29 Feb 2012, 08:32
by Barnes
There are two circuts assosiated with the brake warning lamp (named that to denote it illuminates when there is an issue in the brake system). One is the parking brake handle, which uses a normally open button-type switch which closes when the lever is pulled. The other is called the "pressure differental switch" which is located underneath the master cylinder inside the combination valve (brass block with brake lines going in from the master cylinder and going out to the wheels). You will see a single wire connected to the combination valve. If you unplug this wire and the warning lamp goes off, the pressure differential switch is activated, meaning there is an unequal amount of pressure going to the front and rear brakes. A leak or air pockets in ONE SIDE of the system will cause the switch to activate. You must inspect all brake lines and fittings for leaks and repair as required. If no leaks are found, completely bleed the front and rear of the system. If the light is still on after bleeding, remove the switch from the combo valve and manually recenter the plunger. No TM will have this info, but if you search "combination valve / pressure differential switch" you can find a diagram of what it looks like and what parts have to be moved where.

Re: Parking Brake light stays lighted

PostPosted: 13 Feb 2013, 08:44
by jlwhite29
this is normally a simple fix! ive had a few of these in my shop and all we needed to do was pull/push the bracket that holds the other side of the little s looking connector that comes from the brake switch! It will be the braket that is actually hooked to the brake pedal!

Re: Parking Brake light stays lighted

PostPosted: 20 Mar 2013, 07:24
by EAGLEEYE8789
PLEASE SPECIFY WHAT KIND OF VEHICLE

Re: Parking Brake light stays lighted

PostPosted: 01 Jul 2015, 05:11
by jlwhite29
Its for any HMMWV. The "S" bracket that connects the brake switch to the brake pedal. If you pull or push on the bracked that its attached to it will normally fix your issue.