Might depend on HOW MUCH brake fluid you put in there, but not much.
The radiator holds quite a lot of mostly water, so a dash of brake fluid will quickly become very diluted.
But since the radiator doesn't expect brake fluid, it'd make sense to have it flushed and refilled as soon as possible.
Probably nothing other than brakes that do not work well. You need to have the brake system completely flushed and fresh brake fluid installed or it will ruin lots of expensive parts.
Hot rubber ?
if only for a minute don't worry about it
With the transmission in drive and the parking brake on.
No. Get it fixed as soon as possible. When you have brake fluid leaking out of your rear cylinder, you are putting lubricant on your rear brake. That is keeping that brake from working. It is also letting brake fluid drain out of the car. Your car needs brake fluid to stop the car. If you lose a lot of brake fluid, you will put your foot on the brake pedal and it will go all the way to the floor and nothing will happen. It can be dangerous when you drive down the highway at a high rate of speed and put your foot on the brake pedal and nothing happens. When you crash your car and turn it into a piece of scrap metal, you could get hurt.
short answer......no there will be nothing to prevent the caliper piston from coming out of the body. if that happens you will lose your brake fluid and brake function. you will kill yourself or someone else.
drive with it off and have the parking brake inspected for damage.
If you drive with no antifreeze in your radiator you could ruin the motor. At a minimum you would probably blow a head gasket. The worse thing that can happen is that the motor will freeze up.
brake normally
I don't know, but I have the same problem. My radiator cracked and my battery light and brake light came on ALL at the same time! I got my new radiator today and went to crank the car to drive it to my friend's house and it wouldn't crank. Ggrrrr...I hate being a girl sometimes! == my answer == Commonly this is caused by the failure of the accessory (known as fan or alternator belt) drive belt This causes the alternator to quit working and the engine to overheat, perhaps ruining the engine.
First of all you shouldn't be using water, you should be using engine coolant. And to answer your question, your engine will over heat and you will not be able to drive. You can do damage to your cars radiator running with no coolant.
Check the radiator fan.