History : I've got 135k miles on the clock now (95% freeway). The front pads, rotors and the rear rotors are still original. I had replaced the rear pads at 100k miles.

I have just checked the front brake pads, they are thin like 10-15% left so I think the brake light came from the front pads. I am going to replace the front pads only (diy) since the front rotors are still thick. Will the brake light turn off by itself after the front pads are replaced? Are there any wear indicator or brake sensor I need to replace also? Thanks a lot.

 

My understanding is that the brake wear indicaton is only audible squeaking. The warning light is from low brake fluid. This is normal. As the brake disc pads wear down, the brake piston extends and more fluid goes from the brake fluid container into the brake pistons, causing the brake fluid level to go down.

When you replace the brake disc pads, you will need to force the brake pistons back to get the new brake pads to fit in. This will, in turn, raise the level of the brake fluid. If you had been gradually topping up the brake fluid, when you replaced the brake pads you would need to suction off some of the brake fluid to keep it from overflowing.

 

Thanks Bob, it makes sense. But the strange thing is the brake fluid is full?

 

Well, so much for that idea. Somebody reported the failure of their brake fluid level sensor in the brake fluid container a few months ago. I seem to recall that they tested it by unplugging it? That is one possibility (i.e., sensor thinks fluid is low when it isn't).

 

I hate sensor thing. It usually cost more to fix. I will go ahead to replace front pads and see how's it go! Thanks

 

Looks like it is caused by brake fluid overflow. The fluid was way over the MAX lever. I reduce the fluid to just under MAX lever and the light doesn't come again. I may not need to replace the reservoir cap with switch. I will keep monitoring it few more days and report back.

 

The brake light keep coming back even though I clean the connector of the reservoir cap with switch. I replace it and the problem solved! No more brake light on. Thanks

 

Cool,glad that one is solved.

 

Can you tell me where you purchased the sensor cap. I have the same problem and the brake Light flashes and dings. Btw, the fluid is topped off. Thanks.

 

Your best bet is to buy it from Toyota Service and Parts. I think the part # is 84460-30040, but confirm it first before buying.

 

Thank you hypervish. I will go this route. I assume that I will need the brake light off for inspection other wise I would just pull the connector.

 

Just pull it and short it with a paper clip if that's all you are trying to accomplish.

 

I just placed an online order with Park Place Lexus Parts out of Texas. Good price, hope they come through with a quick delivery. I just want to keep the car original and not have to check the fluid all the time. Thanks for everyone's help.

I just received the part, great price and quick delivery. hypervish, it is not a Toyota part; I checked with a Toyota dealer when I purchased my Type T-IV ATF, so it is only a Lexus part. I'm waiting for some sun before I replace the part; it is an uncommonly cold day for this uncommon Brooklyn winter.