Fluid map
Under-Hood Fluid Guide
Seven fluids keep your car alive. Tap each on the engine bay to see where it is, how to check it and what color it should be.
Quick answer
Check engine oil, coolant, brake fluid, power steering and washer fluid monthly. Healthy oil is amber, coolant is bright (pink, orange, green or blue), brake fluid is clear-gold and transmission fluid is red. Dark, milky or burnt-smelling fluid means service is due.
Tap a fluid under the hood
A typical front-engine layout. Exact spots vary — your owner's manual has the map for your car.
Fluid 1 of 7
Engine oil
Where: Yellow-handled dipstick and the cap with an oil-can symbol on top of the engine.
How to check: Monthly. Engine off and level, wait 5 min, pull the dipstick, wipe, reinsert, read between the marks.
Change: Every 5,000–10,000 mi (synthetic) or as your manual says
Color check
Car fluid cheat sheet
| Fluid | Healthy color | Check | Change interval |
|---|---|---|---|
| Engine oil | Amber, translucent | Monthly | Every 5,000–10,000 mi (synthetic) or as your manual says |
| Coolant / antifreeze | Bright pink, orange, green or blue | Monthly, only with the engine cold | Every 30,000–100,000 mi depending on type |
| Brake fluid | Clear to light gold | Monthly | Every 2–3 years |
| Transmission fluid | Bright red, pinkish | Per your manual — many need the engine warm and running | Every 30,000–60,000 mi (some "lifetime" fills still benefit) |
| Power steering fluid | Red, pink or clear | Monthly on hydraulic systems | Inspect at every oil change; flush ~every 50,000 mi |
| Washer fluid | Usually blue | Whenever the low-washer light comes on | Top up as needed |
| A/C refrigerant | Sealed system — no color check | If the A/C blows warm, have it leak-tested | Only when cooling drops (indicates a leak) |
Puddle under the car? Identify the leak
Car Fluids FAQ
Engine oil, coolant, brake fluid, transmission fluid, power steering fluid (hydraulic systems only) and windshield washer fluid.
Fresh oil is amber and translucent.
Black, gritty oil is overdue for a change; milky or light-brown oil can mean coolant is leaking into the engine.
Coolant is usually bright pink, orange, green or blue and smells sweet.
It is toxic to pets, so clean up any puddle promptly.
Most manufacturers recommend every two to three years because brake fluid absorbs water over time, which lowers its boiling point.
Yes.
Milky oil, oily coolant or dark, burnt transmission fluid are red flags for expensive repairs. Combine the check with a vehicle history report.
Before you buy
Was it maintained — or neglected?
Shopping for a used car? A VIN check shows accident, title, odometer and service history — so you know how the last owner treated it.
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