Err... I think I broke something

My guess, frozen brakes...or tires frozen to the pavement.

 

does it shift into drive and park okay now? any strange noise or behavior?

 

dragging the friction brakes just once is enough to wipe the rotors clean. are in the habit of setting the parking brake? its possible that the parking brakes froze to wheel and broke loose when you popped into drive. releasing the handle wont do it. i have seen that many times when liiving in Michigan. in fact, no one used parking brakes in winter unless on a real real steep hill

but to be honest with ya, usually has to be bit colder than what you had although, freezing is freezing...

 

You washed your car, and yes I know that your parking brake was off, but still, there was enough water to form an ice bond between your shoes/pads and the rotors/drums.

 

Johnathan turn the tunes back up and drive it. I think your listening to intently to the car and you really should ignore it for now and drive it. If it's broke it'll tell you soon enough. But I'll go with the rest of the group and say it was brakes.

 

hmmm. maybe a super frozen chunk of ice formed on your calipers, and when you took off, the ice ground your rotors to a nice shiny silver...

then again.

actually, i know what you are talking about. my front wheels have a light coating of rust on them and have had that since day 2 (like to think they were shiny for at least one day)

since parking brakes only should have been on the rear, really dont have an explanation for them being so smooth. although one good rub will clean them, its actually difficult to do that with a Prius if you are into maxing regen. if being careful, friction brakes dont come into play until going less 8 mph.

makes it tough to "ride the brakes hard" when you are barely moving.

now it makes me think that maybe that bang you heard could be a pad coming loose.

about 20 years ago, i was in a car with a friend of mine and we were driving down the road... all of a sudden, heard a loud bang and the car came skidding to a halt. car was locked up it seemed. hitting the gas, you could feel the car trying to move but no go.

parked it, got out, looked it over, didnt see much wrong with it, got back in, and tried to go... nothing, so the guy put it in reverse, and no problem, puts it in drive and takes off and we could hear parts falling off the car. get out, front brake pad is lying there.

from what we could figure, the pad came loose. wedged itself against the wheel and got stuck. rolling backwards unstuck it and when going forward again, it fell out.

was one of the most comical things i had ever seen. it was like the keystone cops or the 3 stooges or something...

well, to keep all the brake fluid from running out, (it was about half gone as it was), we wedged the shoe back in place, drove nearly 3 miles home and parked it... ya i know... pretty stupid, but that was actually one of the more saner things i was doing at that time of my life.

 

Another vote right here for frozen brakes. I've seen it enough to know it. I think the manual actually mentions not setting the parking brake when it's cold because the rear brakes could bind up.

 

From what you're saying, it really sounds like your parking brake was frozen on. So, when you released the pedal, even though it came up, it didn't actually release the parking brake. Then, when you pushed down on the accelerator, the back wheels broke loose from the frozen parking brake (with a bang, since it's spring loaded) and you were on your way. Seems to me that you should just avoid putting the parking brake on in the winter unless you're on a substantial hill.

This seems like the obvious answer, so I'm not sure why other people haven't suggested it; am I missing something?

 

I've had a similar experiance after washing many different cars. It may not be ice, but rust. Most new cars have brake pads impregnated with metal particles, and the rotor can develop a surface coating of rust in a matter of minutes after getting wet and sitting. Wash the car and then park it without driving it enough to dry off the rotors and they will rust. So will the metal in the pads. In fact, they rust together. The first time you drive it afterwards you will have to break them free, usually with a big bang. This has happened on my Prius, also has happened on my Audi A4.
1 minute of driving cleans the rust off of the rotors and pads.

 

Johnanthan:

That happens all the time in winter after I have to drive through a major snowfall, or now with all the slush and water on the streets.

My condo has heated underground parking, and especially in cold temps driving through deep snow, there is a lot of snow/ice buildup on the wheels by the time I drive into the parking. Of course there is also snow/ice in the wheelwells too.

By next morning, it has all melted but the rotors are still damp and rusty. When I first move the car, nothing happens for a moment then there is a soft "clunk" and the car jerks ahead. Other cars in the parking do the same thing.

As I have to ride the brake at low speed for about 150 metres, by the time I get to the door the grinding sensation is gone and the brakes work normally again.

Note: I always set the parking brake, even when outside. I only had a problem once with my Prius, at -40, when the parking brake was sluggish to release.

jay

 

I may have missed it but are you sure that the loud boom came from your car? That it didn't come from a car in the area that had a big backfire or something? Also, I've created a big boom from previous cars when going over something with one tire which raises it up and then drops it with a thud.

 

That would be one hell of a coincedence if the nearby car backfired right as his car lurched forward. :blink:

EDIT: OK. To be fair, I just read and he didn't explicitly say that his car jumped foward with the boom; I guess I just assumed that from my own experience.

 

It's happened to me before when somebody's car backfires so loudly that it seems to come from anywhere and everywhere. It's a coincidence but not necessarily one where the odds were right up there with winning the lottery. Anyway, I wasn't talking to you

 

If it had happened to me, I'd take it in to the dealership, tell them what happened and see if they can run the diagnostics on it to see if they can find anything wrong. I wouldn't guess. Even if it was frozen brakes or whatever, it still could have caused some damage that you won't find by crawling around on the garage floor.