What's wrong when you notice liquid leaking from your car:
Clear water from the air conditioner is no problem and is perfectly normal. Water that is brownish or green probably comes from your cooling system and should be investigated. If anything else is dripping, however, it could indicate a serious problem. For instance, red, pink, or light brownish greasy fluid indicates a leaky transmission. Black fluid indicates an oil leak. You might be able to locate a leak's source yourself very simply by cleaning the engine with one of the new engine cleaning sprays, driving the car for a few miles, and then seeing where you have streaks of the liquid.

What's wrong when you smell something strange:
A burning odor could be caused by an electrical malfunction, an alternator problem, a loose hose, a belt trying to turn a jammed water pump, wiring trouble, a brake problem, or oil dripping onto a hot exhaust pipe.
Warning: The hydrogen gas from batteries can be explosive, so be careful.
If you smell gasoline, stop the car and look for gas leaking around the engine, fuel pump, and fuel line. If you see any, move away from the car. The hot engine could ignite the gasoline and cause an explosion. The smell of burning oil may indicate that you're low on oil or transmission fluid. The smell of oil or exhaust in the passenger compartment might mean you have a faulty exhaust pipe. A rotten egg odor from the tailpipe area while the engine is running indicates that too much fuel is reaching the catalytic converter because of either faulty ignition or fuel problems.

What's wrong when you feel strange vibrations:
Unfamiliar vibrations can usually be felt throughout the car but most of the time through the steering wheel. They can be the result of fairly minor problems, such as a tire out of balance or some damage to the drive line. However, the causes can be extremely dangerous. If you notice unusual vibrations when you drive, beware: there may be a wheel bearing loosening, a driveshaft universal joint breaking, a transmission giving out, or a drive line part on the verge of failure. A damaged ball joint may be near failure, a wheel could fall off because of loose lug nuts, or the steering could fail due to a loose steering arm under the car. If the situation has developed suddenly, slow to about 15 to 20 kilometers per hour, put on your flashers, and proceed with caution to a nearby service station.

What you should do when your brakes are not working properly:
Never drive with defective brakes. If your brakes are sticking, consult a mechanic promptly. If you ever depress the brake pedal and your car won't stop, pump it quickly several times. If it still doesn't stop, use the parking brake (hand brake). If you're making an emergency stop, apply the brake fully and quickly. This can cause your wheels to lock up, so be prepared for a skid. Otherwise, apply the brake gently and pull out of traffic as quickly as possible. Then have the car towed to a brake shop.
If your car doesn't have a brake warning light, be alert for increased pedal travel. If the pedal moves farther than usual, that's a symptom that fluid is low in the entire system or that one half of the system has failed. Have your brakes checked at once by a certified professional.

What's wrong when your window leaks when it rains:
Make sure the rubber gasket around the top of the glass covers both sides of the glass when the window is closed. The rubber gasket may simply be out of place.