Peek under your car’s hood and you will find reservoirs or dipsticks to access a bunch of different fluids. Each serves a critical function, and there are symbols on the lids or access points so you can figure out which is which. But what happens when you find the fluid somewhere it isn’t supposed to be, like on the ground underneath your car?
Leaks are an all-too-common by-product when you own a car. Knowing how to identify car fluid colours can help you avoid even more frustration with costly diagnosis or repair bills and keep your car-related expenses at a minimum.
Car fluid colours: A primer
If you see fluid under your car, in the engine bay or somewhere else, the colour can help identify what the fluid is. Leaks can be a serious issue, and some context between the colour and location can help you determine what the fluid is and where it’s from. If you know where the problem is, you can fix it and hopefully avoid lasting damage.
Some systems use fluids that either look similar or are the same, and it could complicate your diagnosis. You’ll still be able to narrow down potential issues, and that’s a great thing especially if you’re working on your own vehicle.
What colour is power steering fluid?
A red, light brown or clear leak could be power-steering fluid, the hydraulic fluid used for assisting your steering effort. Some cars instead use automatic transmission fluid, which is red or pink, because it stays more fluid in cold weather. When the fluid is aged or contaminated, it turns amber or dark brown and smells burnt.
Where you might find it
If the power-steering fluid is leaking, it spills from the front of your car, under the engine bay or bumper. It could also spray inside the engine compartment if under pressure. That could be a fire risk.
What it might mean
Leaking fluid from the power-steering system could be a signal the power-steering pump seal is blown; the power-steering gear is leaking from the seals; or one of the power-steering hoses or power-steering fluid cooler is blown. The leak could also be as simple as a loose hose clamp.
What colour is brake fluid?
Brake fluid starts out clear in the container and turns a light amber to dark brown or almost black over time. It feels slick to the touch but is not a good lubricant. It’s also caustic and can cause paint to peel if you get it on your car. It’s used as a hydraulic fluid forced through the brake lines toward the callipers or wheel cylinders, using friction to slow your car.
Where you might find it
One of the most common places to find brake fluid leaking is in the flat inner surfaces of your rims. You may see the fluid drip from a frame rail where the brake lines run to the back wheels or from under the hood near the firewall.
What it might mean
A leak onto the wheels could be a sign that a calliper or wheel cylinder has a hole. Leaks may also appear along cracked or rotten brake fluid lines. It’s a critical repair for your safety, so don’t put it off.
What colour is motor engine oil?
Engine oil almost always starts out as a honey brown colour with the exception of a select few synthetic oils like Royal Purple. As you drive and the motor oil circulates, it gets darker. Diesel engine oil quickly turns pitch black from soot.
Where you might find it
You’ll find motor engine oil under the engine when it’s leaking, either in small drips or a puddle. Oil often washes down from where it’s leaking, so it could coat an area of the engine near your leak. Most cars today also have oil coolers near the radiator, so you could have drips from under the front bumper area, too.
What it might mean
Engine oil often leaks from the crankshaft oil seal, oil pan gasket or valve cover gasket. The leak could also stem from a blocked PCV valve, or the engine oil cooler or hoses could be leaking. But first, check the oil pan drain plug and oil filter—they may just be loose.
What colour is coolant?
Engine coolant is another fluid that isn’t always consistent in colour. Depending on the type of coolant, it could be green, orange, yellow, turquoise, pink, blue or purple. However, it’s noticeably more vibrant than other fluids and doesn’t feel oily or greasy. Antifreeze circulates inside the engine to absorb heat and carry it to the radiator to prevent overheating. The coolant is also necessary for carrying heat from the engine bay into your car.
Where you might find it
Leaking coolant can come from a variety of areas. It could be a puddle under the front bumper or the engine, or it could be on the passenger side floor mat inside your car. You might also see it pooling in crevices on top of the engine block.
What it might mean
Coolant under the front bumper usually points to a radiator leak or coolant hose issues. If the fluid is on or under the engine, it may be a problem with the thermostat gasket, water pump leak, hoses or even a head gasket leak. If you have coolant inside the car—it smells like burnt sugar—your heater core is probably done for.
What colour is transmission fluid?
The fluid could be red or pink if you have an automatic transmission; clear or light brown if it’s a manual transmission; or green, amber, purple, blue or red if you drive a car with a continuously variable transmission. This fluid acts as a lubricant to prevent wear on parts. It also cools the internal components and acts as hydraulic fluid to operate functions within the valve body.
Where you might find it
The fluid could be on or by the radiator, under the engine bay, on hoses in the engine bay or under the middle of your car toward the front.
What it might mean
Leaking transmission fluid signifies a few potential problems. It could be a leaking hose, such as the transmission cooler supply hose, or a leak at the radiator where the cooler is. The fluid leak could also come from a blown seal on the transmission input or output shaft, a transmission oil pan gasket issue or even a cracked case.
Nelson Xavier Ssenyange
Team Leader
Germax Autos, Spares & Garage Ltd
Lukade Road, Naalya
0779250886/0752088734
