Fluid color chart
- Clear, watery, no smell — AC condensation (normal in Texas summers)
- Green, orange, pink, sweet smell — coolant
- Red or pink, oily — transmission or power steering fluid
- Light brown to black, slick — engine oil
- Clear to yellow, slippery, near wheels — brake fluid
- Blue — windshield washer fluid
The cardboard test
Slide white cardboard under the engine overnight. The color and position of drips tell a mechanic a lot: front center usually engine or coolant, middle transmission, near wheels brakes.
Which leaks are urgent?
Brake fluid leaks are a safety emergency. Coolant leaks lead to overheating. Oil leaks onto the exhaust are a fire risk. AC water is normal.