Brake lights, The brake lights are always in the ON position... Options

[Cire]

I noticed the other day that when I put in the key and turn on the car that the brake lights came on. I thought it was one for German engineering but then a friend told me that my brakes were always on and they couldnt tell when I was slowing down or stopping. So.....

I pulled the wheel off and looked at the master cyl. I see there are 2 wires that COULD connect to the master cyl brake light switch. However there is only one plug on the switch. So I tried them both with no (Its hard when you work on brakes alone) noticable change.

I pulled up my favorite 914 world site and did some reading. I saw one post where someone said that the pressure on the master cyl wasnt being released therefore leaving the vehicle in a constant state of BRAKES ON. So I went over and pulled up the pedal and the light went out.

So a few questions for the gurus out there.
1 - What wire should be connected to the switch?
2 - Is that the correct switch to only have one connector?
3 - How do you resolve the brake pedal coming back far enough to disengage the brake sensor?

4... Is there anything else I am missing or overlooking? Plently of fluid. = )

Thanks all.

Eric

[john rogers]

None of that has anything to do with the brake lights coming on. The switch that turns on/off the brake lights is under the floor board and has a round disc shaped piece of metal on the rod that accuates the master cylinder. There is a lever on the switch that this disc hits that turns the brake lights on/off. There is a very small adjustment screw on the backside of this switch to allow adjustment of the lever travel, do not bend the lever.

What happens in many cases is the lever gets bent somewhat from old age and use and then will slip around the metal disc so the swich has the brake lights on all the time.

[Cap'n Krusty]

None of that has anything to do with the brake lights coming on. The switch that turns on/off the brake lights is under the floor board and has a round disc shaped piece of metal on the rod that accuates the master cylinder. There is a lever on the switch that this disc hits that turns the brake lights on/off. There is a very small adjustment screw on the backside of this switch to allow adjustment of the lever travel, do not bend the lever.

What happens in many cases is the lever gets bent somewhat from old age and use and then will slip around the metal disc so the swich has the brake lights on all the time.

Not to sound harsh or anything, but I don't think you could bend that lever on purpose, at least not without a torch or a vise and a long bar. Bending from old age is absolutely out of the question ........... This is a CLASSIC symptom of a leaking master cylinder and pedal assembly bushings that are swollen from absorption of brake fluid. From the original post, it's clear the disc is in the right position, as the lights go out when the pedal is pulled back. The Cap'n

[Cire]

None of that has anything to do with the brake lights coming on. The switch that turns on/off the brake lights is under the floor board and has a round disc shaped piece of metal on the rod that accuates the master cylinder. There is a lever on the switch that this disc hits that turns the brake lights on/off. There is a very small adjustment screw on the backside of this switch to allow adjustment of the lever travel, do not bend the lever.

What happens in many cases is the lever gets bent somewhat from old age and use and then will slip around the metal disc so the swich has the brake lights on all the time.

Not to sound harsh or anything, but I don't think you could bend that lever on purpose, at least not without a torch or a vise and a long bar. Bending from old age is absolutely out of the question ........... This is a CLASSIC symptom of a leaking master cylinder and pedal assembly bushings that are swollen from absorption of brake fluid. From the original post, it's clear the disc is in the right position, as the lights go out when the pedal is pulled back. The Cap'n

Its a brand new 19MM master cyl. I just installed it about 2 months back. It doesnt leak anywhere that I have ever seen. Not in the foot area or near any of the brakes/wheels or even the T.

Does anyone have pictures of that wheel and stuff that actuates the brake light? Which wire gets hooked up?

Help... = )

Eric

[Cire]

WOW!!!!!!!!!! I am so glad I found this post... CRAP. I pressed the little black button.... Works great. Silly stuff!!!! I am glad I didnt rip apart the brake pedal area to find that it was a 2 second button on the master cyl.

Eric





The 914 is equipped with a master cylinder that contains a brake warning switch built-in. this switch is activated when there is low pressure in the master cylinder. When the system senses a failure, the brake warning lamp in the cockpit flashes in the same manner as it does when the emergency brake is pulled. So far, I have seen two varieties of the master cylinder switch. One type indicates low pressure when the pedal is pushed down to the floor, and then resets when the pedal is lifted. The other variety indicates a pressure failure, and then remains locked until manually reset. To reset the switch, you need to removed the belly pan from underneath the rack and pinion. Then you need to locate the master cylinder, and remove the small plastic boot covering the electrical switch. The plastic boot covering the switch is shown in Figure 1. The switch has this tiny little plastic button that needs to be pushed in towards the master cylinder. Doing this should reset the system, and turn off the brake system warning lamp.
Sometimes these switches are known to fail. If your brake pressure seems fine, but your switch keeps getting triggered, you might want to replace the switch. Unfortunately, the cost to purchase a new switch is almost half the cost of a new master cylinder. Good used ones are available though, salvaged from worn-out master cylinders.

[Dave_Darling]

Its a brand new 19MM master cyl. I just installed it about 2 months back...

DING DING DING DING!!

That's when this happened. The washer in the middle of the pushrod goes on the other side of the lever on the switch. It goes on the not-so-obvious way. BTDT.

--DD

[RJMII]

Its a brand new 19MM master cyl. I just installed it about 2 months back...

DING DING DING DING!!

That's when this happened. The washer in the middle of the pushrod goes on the other side of the lever on the switch. It goes on the not-so-obvious way. BTDT.

--DD

Dave, do you have a diagram handy?

(i'm looking at grp 7 diagram in the exploded view diagram pdf of the hsop manuals, and don't see the washer... either I'm tired, or I'm just missing it?

[Dave_Darling]

The "washer" is the part that the arm for the switch rides on. Part 19 in the following pic:

http://www.pelicanparts.com/914/Parts/Peda...al_assy_big.htm

--DD

[john rogers]

Dave is right, small lever could be on the wrong side of the washer and no matter what some say it is easily bent and there was just a post about this a short while ago and the person bent the lever arm instead of using the adjuster on the back of the switch.