Brake Pad Wear Indicator Warning Light

[rene525d]

Does it even happen to you that during very hard braking , the brake wear indicator light lights up? Turning the engine on/off clears the warning light and something when I brake hard once again it comes back on. There is still a lot of thickness on the pads.. Is there any other occurrence where the brake light lights up on the boxster, apart from when the sensor makes contact due to thin pads?

[Timco]

Were new sensors used on the last pad swap? If one triggers, it has to go I was told. Or it may just be close enough to whine a bit. Mine would only trigger after a car wash. Then would reset, but the pads were thin.

[rene525d]

Everything was replaced last September... I can't see how it only lights up on hard braking. I think it can be the low fluid warning, maybe during hard braking the level goes slightly down as the pistons are all extended to their limit. However on inspection, brake fluid is just below the max.

[Timco]

Originally Posted by rene525d

Everything was replaced last September... I can't see how it only lights up on hard braking. I think it can be the low fluid warning, maybe during hard braking the level goes slightly down as the pistons are all extended to their limit. However on inspection, brake fluid is just below the max.

Follow each wire? Sounds like an intermittent short to ground. Brake spoilers in place on all 4? Wire melted slightly? Chaffing if not in grommets?

[san rensho]

Disconnect those pesky brake wear sensors and zip tie them up, then you will never have a problem. Its so easy to see the brake pad thickness that the wear sensor makes no sense.

[thstone]

The brake sensors are about as simple as can be: There is a loop of wire that goes to each brake pad and when the pads wear down, the wire is scored by the rotor which breaks the loop/circuit and the dash light is illuminated. There is no check for fluid level or anything else associated with the braking system.

Hence, if the brake dash light is coming on during hard breaking AND the pads are all in good condition, you most likely have a bad brake sensor/wire.

The fault could be an intermittent connection where the brake sensor connects to the rest of the wiring harness. Unplug each sensor and plug it back in and then go do a few hard stops to see if that fixes the problem.

They are also known to melt under hard braking (Melted Brake Sensors).

Or you might just be lucky and got a bad sensor cable when they were replaced.

Perform some simple troubleshooting to find which brake sensor is faulty (test one at a time) and then replace those found to be faulty. Or bite the bullet and replace all four and you should be good to go.

Like others, I removed all of the brake sensors from the pads and zip tied them out of the way. Manually checking pad wear takes about 20 secs per wheel using a small mirror and a flashlight. Problem solved.

[rene525d]

Thanks thstone just what I wanted to confirm..... that only the brake sensors can light the error bulb. Cheers. Advice taken.