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My mystery brake problems continue

My mystery brake problems continue

I've previously reported two instances of brake issues. Both related to exceptionally high energy usage reported. The first time it lasted quite a while and resulted in high energy usage and brake dust built up on one fender and the smell of burning brakes. It broke free eventually and energy usage plummeted. Tesla service found nothing wrong.

The second time it happened, it was just for a day. Same super high energy usage and this time the sound of something grinding for half a day. Then it broke free. Tesla service found nothing wrong.

This weekend I had another issue with brakes. I was braking, not hard enough for ABS, and then felt the brakes let go for a fraction of a second. What's even weirder is about 5 minutes prior I was accelerating on to the freeway. Peddle to the floor (of course) and at about 50mph it lost power. Barely accelerating. Took about 10 seconds to get from 50 to 60mph. Felt like the power was cut, or brakes were applied. My foot was on the floor. Did it three times in a row and then it worked fine. Not in chill mode. Also, when just lightly touching throttle pedal, energy black bar pegged to the max on the right. No warnings on the screen. Tesla did remote diagnostics and found nothing. Scheduled to bring it back in, but not super thrilled about driving around a car with potential brake issues.

Anyone else have similar issues? Any ideas on what to check?

hokiegir1 | 2019年5月20日

Do you frequently drive on gravel roads? Or park in a moderately sized puddle?

slingshot18 | 2019年5月20日

Never been on a gravel road. My parking lot does get puddles when it rains, but I try to avoid them because I don't like getting my shoes wet.

The pebble in the brakes thing was investigated, but it wouldn't account for all the symptoms.

Sparky | 2019年5月20日

Next time you see slow acceleration and high energy bar let the car slow to a stop without applying the brakes and put your hand behind each wheel to see which brake area is warm. If you have a hot brake it's being applied and if it isn't because you're pushing the brake pedal the issue is serious and needs Tesla warranty repair immediately.

And I'm just wondering if you may be inadvertently pushing the emergency brake (park brake button) while driving. That could account for it without anything being wrong with the car.

hokiegir1 | 2019年5月20日

I was just thinking how wet brakes that aren't used often (which ours generally aren't because of regen braking) can cause them to stick when parked, and then they don't dislodge properly when you start going. Something to do with rust. I'm not entirely clear on how it happens, but it happened to another of our vehicles that sat for awhile (not in a puddle either) and had similar symptoms.

slingshot18 | 2019年5月20日

@Sparky I've checked brake temps with an IR thermometer last time it happened and shown double the temp on one side. But then when Tesla gets the car, everything works fine.

The weird accelerating issue I had though, if it was the brakes, was far more severe than anything I've seen before, and would mean the intermittent nature of it is of an odd variety.

Certainly was not pressing the parking brake when accelerating. And previous time, wasn't pushing the parking brake for half a day consistently.

Maybe the a parking brake bug where the car is turning it on without me hitting the button? But when you hit the parking brake when driving, it shows a warning on the screen. I had no warnings.

Bighorn | 2019年5月20日

I had a binding caliper for about 1000 miles on a trip which had freed up when I dropped in for service while passing through Phoenix. Nothing IDed. Eventually both front calipers were found to have corroded and frozen inboard pistons. A northern issue based on road salts. They’ve since added a scheduled brake lubrication.

slingshot18 | 2019年5月20日

I'm in southern California, with no road salt. Last time in they disassembled the brakes and found no evidence of anything. Said it's working perfectly.

I firmly believe my first instance was a binding caliper based on dust, smell and performance once it "let go." But recent issues make me think it's something else, either a bug or something flaky with the car/software.

Sparky | 2019年5月20日

@Bighorn; what interval do they specify for brake lubrication?

Bighorn | 2019年5月20日

The guys who diagnosed mine in St Louis suggested every 2 years, but the official schedule became every year/12.5k miles, I think, which ain’t happening since I’d have to service them half a dozen times a year which makes zero sense.