Smoke Coming From From Tires?

[808-lexus]

i've never had this happen before, but today, i was driving downhill on a narrow windy road and when i got to the bottom, i realized that it was somewhat hard to stop the car and that there was some smoke coming out of the front tires. it sure smelled like brakes but it couldn't have been because the brakes were just replaced about 2 months ago. what could this mean??

[SRK]

The smoke is the result of the front brakes overheating, and the increased pedal pressure you detected is called "brake fade" as the heated pads no longer produce the friction they did when cold. New brakes overheat just like old brake pads - and brake fluid can boil too. Brake rotors that have been turned or worn too thin will overheat more quickly (less of a heat sink) but brand new ones will overheat too.

The trick is to descend the hill more slowly and use the brakes less. As an old truck driver with mountain experience I've encountered overheated brakes before. The physics of braking is - double the speed and braking force must increase four times, double the weight and brake force must increase two times. Double both and brake force increases eight times. Weight is not the issue in a car unless you are towing a trailer, but speed definitely is.

One of the reasons Lexus demands that brake fluid be flushed every few years is that as brake fluid absorbs moisture from the air it's boiling point is reduced, and in a situation like you encountered it is possible to boil the fluid in the calipers. Then you would have almost no brakes at all.

[wwest]

The smoke is the result of the front brakes overheating, and the increased pedal pressure you detected is called "brake fade" as the heated pads no longer produce the friction they did when cold. New brakes overheat just like old brake pads - and brake fluid can boil too. Brake rotors that have been turned or worn too thin will overheat more quickly (less of a heat sink) but brand new ones will overheat too.

The trick is to descend the hill more slowly and use the brakes less. As an old truck driver with mountain experience I've encountered overheated brakes before. The physics of braking is - double the speed and braking force must increase four times, double the weight and brake force must increase two times. Double both and brake force increases eight times. Weight is not the issue in a car unless you are towing a trailer, but speed definitely is.

One of the reasons Lexus demands that brake fluid be flushed every few years is that as brake fluid absorbs moisture from the air it's boiling point is reduced, and in a situation like you encountered it is possible to boil the fluid in the calipers. Then you would have almost no brakes at all.

By 1993 the LSes brakes had been upgraded twice as a result of the problems you just had.

If you often travel down that winding road then I would seriously consider upgrading the brake system, new rotors, calipers, to at least a late '92

[Jim W]

The smoke is the result of the front brakes overheating, and the increased pedal pressure you detected is called "brake fade" as the heated pads no longer produce the friction they did when cold. New brakes overheat just like old brake pads - and brake fluid can boil too. Brake rotors that have been turned or worn too thin will overheat more quickly (less of a heat sink) but brand new ones will overheat too.

The trick is to descend the hill more slowly and use the brakes less. As an old truck driver with mountain experience I've encountered overheated brakes before. The physics of braking is - double the speed and braking force must increase four times, double the weight and brake force must increase two times. Double both and brake force increases eight times. Weight is not the issue in a car unless you are towing a trailer, but speed definitely is.

One of the reasons Lexus demands that brake fluid be flushed every few years is that as brake fluid absorbs moisture from the air it's boiling point is reduced, and in a situation like you encountered it is possible to boil the fluid in the calipers. Then you would have almost no brakes at all.

By 1993 the LSes brakes had been upgraded twice as a result of the problems you just had.

If you often travel down that winding road then I would seriously consider upgrading the brake system, new rotors, calipers, to at least a late '92

[Jim W]

When I travel down long steep grades, I shift the transmission to a lower gear, so that helps to keep the speed down & I don't have to use the brakes so much. I tow a travel trailer with my Suburban keep it in second gear going down steep mtn roads. When I do steep on the brakes, I step on it a little harder to slow faster & then keep my foot off the brake until I need to slow it more. Be sure you don't ride the brakes.

[rayikone]

Sometimes that happens when you drive with the parking brake on.

[808-lexus]

while i was driving down that hill, i had it in a lower gear so i didn't have the use the brakes much. it's not the first time i went down that hill so this happening was kind of strange.

the car does some strange things sometimes...like it had a mind of its own. maybe the car's posessed! haha!

[808-lexus]

ok, so, i went on a four-hour drive today (two hours going, two hours back) and experienced the "spongy" brake pedal and that weird burning brake smell again. on the way back home, everytime i pressed the brake, it pulsated a lot; even when i was going very slow. do i need to get the brake fluid flushed out? do i need to replace the rotors?

[etex]

Sounds like both a brake fluid flush and new rotors might be in order.

[808-lexus]

i was reading something about ugrading the stock brake system to a larger brake system. i read that someone replaced his stock brakes with brakes from a supra twin turbo. that means bigger calipers, bigger rotors, and a for sure need for rims (haha!).

should i upgrade the brakes to a system that has more optimal performance or just replace the current rotors with stock rotors?

what would you recommend i do?

[falciott]

i was reading something about ugrading the stock brake system to a larger brake system. i read that someone replaced his stock brakes with brakes from a supra twin turbo. that means bigger calipers, bigger rotors, and a for sure need for rims (haha!).

should i upgrade the brakes to a system that has more optimal performance or just replace the current rotors with stock rotors?

what would you recommend i do?

808, are you somewhat mechanically inclined? If so, then the brake job is super easy! I had fading problems as well,plus vibrating in the sterring wheel, so i changed the rotors to Brembo rotors, and installed ceramic pads, and flushed out the fluid. Excellent braking now,with no fading, and saved some decent money by doing it myself.

[808-lexus]

well, i'm still learning about cars so i don't exactly trust myself doing brakes yet, but my boyfriend knows a lot about cars and is going to school for auto mech. he owns a '95 tercel and a '94 supra. the supra is stock but he modded the tercel - motor swap, transmission swap, added turbo, etc.

anyway, i'll ask him if he can do the rotors. will these rotors fit in the stock rims? are they just bolt-on?

[falciott]

well, i'm still learning about cars so i don't exactly trust myself doing brakes yet, but my boyfriend knows a lot about cars and is going to school for auto mech. he owns a '95 tercel and a '94 supra. the supra is stock but he modded the tercel - motor swap, transmission swap, added turbo, etc.

anyway, i'll ask him if he can do the rotors. will these rotors fit in the stock rims? are they just bolt-on?

Sorry, slow reply, i was away vacationing, anyway, if your bf did motor swaps and such, then he should be able to do a brake job. You have a 90 LS? Then you have 15" rims if they're stock, so only stock rotors will fit. You can get the rotors from tirerack.com , and shipping won't be that crazy either to Hawaii, unless you trust yourself with some other brand at the local autoparts.. I wouldn't. Good luck.