It’s a $2 USD part, and every Toyota has one. It’s a little elastomeric cushion that goes on a tab on the brake pedal that both deadens the pedal top-out when the brake is released and depresses the pin on the normally-open brake light switch.
My across-the-street neighbor came by as I finished my bike ride on Wednesday to tell me that my lights were on. The headlamps and parking lights were off, but the taillights were on. I almost immediately knew what the problem was. Opening the driver’s door, I saw the two broken pieces of the cushion sitting on the floor mat. With age, the elastomer gets hard and brittle, and eventually the insert point that holds it to the brake pedal breaks, and the cushion head falls off. The pin on the brake light switch now aligns perfectly with the hole where the cushion attaches, and even with no pressure on the pedal, stays open and the lights stay on. If you don’t notice this quickly, the battery runs down and dies.
It’s very Japanese how the engineers at Toyota simplified the design so the pedal rest-position adjuster is the brake light switch body instead of having a separate stop and brake light switch (I think my Nissan had seperate parts). They never forsaw this issue because they didn’t expect a condition to arise that the cushion actually failed. They were thinking that the duty-cycle of the car would be shorter than the lifetime of the rubber compound, and the likelihood of a failure was nil. Simply moving the hole in the brake pedal by 3mm would prevent this condition – even without the cushion, the brake switch would still function. This would probably offend someone’s design sensibilities because the switch would be striking the cushion off-center, so the thought probably never made it past the eureka moment.
A zip tie through the cushion hole temporarily fixed the problem until I could spin by Toyota Parts and get a new gummy-bear soft cushion from Harold. It is all good again. Seems that these get hard and fail around 12-17 years-old, regardless of mileage. If you have a Toyota, replace your cushion at 10-years and save youself from coming back to a mysteriously dead battery.
I had the same problem, I noticed the brake lights remained on. I saw the cusion on the floormat with curiosty. At first i thought it was the switch until I checked the switch with a meter.Then I saw where the cusion came from. A trip to Toyota and $1.03 later I was back on the road.
P.S. 1990 Corolla 19 years old.
Thanks