There are a variety of different fluids used in today’s cars and trucks. You have engine oil, antifreeze, power steering fluid, windshield-washing solution, brake fluid and others. While automotive engineers work hard to design their vehicles to keep these fluids “contained,” we all know that sometimes they end up on the garage floor. And what’s maddening is that unless you are skilled at identifying car fluids, it’s hard to know what the devil is leaking -and if it’s a serious problem.

In this article, we will cover the six most common fluid leaks from your average car—from the leaks that mean that something is failing, to the leaks that really mean absolutely nothing. Let’s try to figure out what fluid is leaking from your car and what you should do about it.

First, make sure it’s your car

This might seem silly but if you see a puddle of fluid on your garage floor, be sure it’s from your car. You would be surprised how many people are fooled by this and the leak they see on the garage floor is actually coming from another vehicle that was parked in the same place.

To be absolutely sure your car is the one leaking and also to find out what type of fluid it is, an old trick is to slide a sheet of white poster board under your engine and transmission and let it collect drips overnight. The next day, not only will see the color of the fluid, you’ll see the approximate location of where its coming from.

Water leaks

Air conditioners in cars and trucks do two things: first, they take the warm air inside the passenger compartment and blow it through an evaporator core which cools it down. The second thing they do is remove the moisture from the air and drain it through a rubber hose that empties under the car. So, on hot, humid days, if you have your car’s AC on, water will almost pour out of the air conditioner drain onto the ground.

By the way, the air conditioner drain hose is usually near the area where the front passenger rests their feet. If you have a large SUV with front and rear climate control, it’s possible to have two evaporators and two air conditioner drains, one in front and one in the rear.

Oil Leaks

Engine oil may vary in color from light amber to dark brown. Generally, engine oil leaks aren’t terribly serious unless a lot of oil is dripping out. You still have some time to get it to a mechanic and have it checked out. Some oil leaks are relatively easy to fix, such as those from the engine’s valve cover gaskets but those coming from head gaskets and rear main seals are a different affair. They can be more expensive to repair.

By the way, if you know you have an engine oil leak, check your dipstick frequently. It is not a good idea to drive a car that is low on oil. The engine will possibly overheat and damage itself.

Radiator coolant Leaks

Radiator coolant is usually a 50-50 mixture of antifreeze and water. In the old days, this mixture was a light green color. But today, says our article consultants at Central Avenue Chrysler of Yonkers, a local Chrysler, Dodge, Jeep, Ram dealer in Yonkers, NY, radiator coolant comes in all sorts of colors. Most antifreeze is still green but Honda provides a blue coolant, for example, Mercedes uses clear one and Toyota uses red.

The main component of antifreeze is a chemical called ethylene glycol and it has a sweet smel,l and also a sweet taste. Don’t taste it, though, it is highly poisonous! Also, if you have a lot of antifreeze pooling under your car, do not let animals or small children anywhere near it. They are likely to lick it and ingest enough to poison themselves.

If you suspect you have a coolant leak, take a quick glance at the coolant overflow tank, it is usually see-through and has “high” and “low” markings on it. If it’s empty, or you aren’t sure what you are seeing, let your engine cool completely and look in the radiator. (Do not remove the radiator cap on a hot engine!) If you can’t see any coolant when you are peering down into the radiator, you may have a leak.

By the way, you don’t want to drive a car that has lost a lot of coolant. It can overheat and some cars are quickly ruined when this happens. If your coolant is low, keep an eagle eye on the temperature gauge and don’t let it get “into the red.” Or better yet, tow it to where it can be fixed.

Transmission Fluid Leaks

Automatic transmissions use a red, oily fluid. The most common place for a transmission fluid leak on a front-wheel drive car is by the axle seals; on a rear-wheel-drive car it is on the output shaft seal. If you do see red fluid under your car, it’s a good idea to check the level of your transmission fluid. Top it off with a manufacturer’s approved fluid if it is low. If you are leaking a lot of fluid, have a mechanic look at it.

Gear Oil Leaks

Gear oil in manual transmissions and differentials fluid is very thick and has a sulfur smell. It is usually dark brown, or amber if it’s new and clean. Gear oil leaks are generally from old seals and they usually are small leaks. Gear oil can also leak from the wheel bearing seals or rear axle seals. If you have a four-wheel-drive car, gear oil can leak from the front axle as well. Again, if a lot of oil is coming out, see your local mechanic.

Power Steering Fluid Leaks

Power steering fluid can be hard to describe because some manufacturers use transmission fluid (which is red) and some use their own brand of power steering fluid (which can be many colors.) If you think you might have a power steering fluid leak, the first place you should look is at the power steering reservoir. The reservoir should have high and low markings and it should be easy to see whether the fluid is low. Other signs that your power steering fluid is low is that the power steering pump may make a whining sound when you are turning the steering wheel.