illustration of car dashboard lights

​5 essential fluids to keep your vehicle running

On the Road 4 min read

I work full-time and then some; combine that with a toddler, an infant, a husband who runs his own business, and a packed social schedule, and I’ve come to realize that the essential fluids to keep me going are coffee and wine.

It’s not terribly different when it comes to the fluids in my car. Our vehicles have some essential fluids that keep them humming along. Beyond fuel—kind of an obvious one—here are five of the most important fluids and how to recognize if your ride has a problem with one.


  • Why it’s important: The oil pump and engine oil are the heart and blood of your vehicle, respectively. They move oil through the engine, lubricate the moving parts to reduce friction and wear, and keep the engine clean.
  • How to maintain it: Check your oil level once a month. When it comes to changing it, stick to the frequency suggested in your owners’ manual. The old adage of changing oil every three months or 3,000 miles still holds true for many a used car, but a lot of newer vehicles are engineered to go even longer.
  • How to know if there’s a problem: If your vehicle has an oil leak, you may notice black or brownish drops on the ground beneath its front end. You might also notice an indicator on your dash—a low oil alert is usually an orange-colored light while a low oil pressure alert is red. If you see the latter, you need to address it ASAP. Your vehicle’s telling you that it’s more than three quarts low and you’re heading toward a blown engine.

Transmission fluid

  • Why it’s important: Transmission fluid does for the transmission what oil does for the engine. It lubricates the moving parts and prevents build-up by acting as a cleaning agent. It also helps cool the transmission.
  • How to maintain it: A rule of thumb is to change your transmission fluid every 60,000 miles. Again, refer to your owners’ manual for the recommended maintenance schedule for your vehicle.
  • How to know if there’s a problem: If your vehicle has a transmission fluid leak, you may notice red- or rust-colored drops on the ground. Even a slight drip should prompt a trip to a repair shop. If you start your vehicle and notice that it’s more of a steady leak than a drip, have it serviced immediately. Low transmission fluid will cause your vehicle to experience delays when shifting gears or will result in a harsh shift. You might also notice a feeling of slipping between gears upon acceleration.


  • Why it’s important: This mixture of water and antifreeze is stored in your vehicle’s radiator and helps dispel heat from the engine.
  • How to maintain it: Again, consult your owners’ manual for the best frequency at which to change your coolant. Most recommend it be changed every 30,000 miles.
  • How to know if there’s a problem: There are a few tell-tale signs of a coolant leak. You might see your temperature gauge rise or notice your heat isn’t working as efficiently as usual. You might also detect a sweet smell when your vehicle warms up or see smoke under or near the hood. Most newer vehicles have a low coolant light on the dash. If you see it light up, get your vehicle checked.

Brake fluid

  • Why it’s important: Your brake system is hydraulic, meaning it uses fluid to create pressure. That pressure moves the braking components—under extreme pressure and temperature—to cause the vehicle to stop.
  • How to maintain it: Vehicle manufacturers generally recommend changing your brake fluid every two years unless you’re advised to do so sooner because of a problem.
  • How to know if there’s a problem: A fluid leak can appear anywhere beneath the brake lines, which run throughout the chassis of the vehicle. If the fluid’s getting low, your brake pedal might offer a spongier-than-usual resistance when you press it, or may suddenly drop before becoming firm. Most newer vehicles have a red warning light on the dash to indicate a problem. If you have a brake problem, get to a repair shop ASAP. If need be, have your vehicle towed there. Don’t take a chance when it comes to your brakes.

Power steering fluid

  • Why it’s important: Similar to brake fluid, your power steering is a hydraulic system. In this instance, the hydraulic pressure makes steering easier.
  • How to maintain it: Generally speaking, there’s not a specific mileage interval at which you should change your power steering fluid, though the owners’ manual for newer vehicles may include a recommendation. A good habit is to check it once a month or so—when you check your oil—to make sure it’s at the right level.
  • How to know if there’s a problem: If there’s a leak, you may notice drops on the ground beneath the front end. If your steering wheel is difficult to turn or you hear a whining noise when turning, check your fluid level. There is no warning light on the dash for this fluid, so it’s important that you remember to check the level regularly.

Another helpful tidbit: check your windshield wiper fluid. It’s not just blue tinted water; it’s more important than that. It contains chemicals to help the wipers clean the guck off the windshield and keep the glass frost free in cold weather. So, check it often, especially in the wet, wintery months. It’s just another essential fluid, right up there with coffee and wine.

This information is provided as general guidelines only. Always follow the specific maintenance and repair recommendations in your vehicle owner’s manual.

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