Monthly fluid checks take five minutes and catch most slow-developing problems before they cause roadside breakdowns. The fluids to check: engine oil, coolant, brake fluid, power steering fluid, transmission fluid (if equipped), and washer fluid.
Engine oil: dipstick check with engine warm but off. Should be between the marks. Color should be amber to medium brown — black or gritty means overdue for change.
Coolant: check the reservoir level, not the radiator cap. Should be between the cold/hot marks depending on engine temperature. Color should match what's in the system (don't mix colors).
Brake fluid: reservoir under the hood, usually translucent so you can see the level. Should be between max and min marks. Dark brown or black fluid indicates moisture contamination — needs flush.
Washer fluid: easiest to check, easiest to forget. Top up monthly so you're never caught without it in a sudden storm.