A car's fluids are vital to a car's well-being and longevity. We started off with engine fluids
. This time, we talk about the one that make the car move, turn and stop.
This often overlooked fluid is an important part of your vehicle's ability to stop safely. Brake fluid, when functioning properly, is an incompressible medium that relays the pressure of your foot on the brake pedal, throughout your hydraulic braking system and signals the callipers to clamp against the discs.
The problem is that brake fluid can overheat, which produces bubbles. Bubbles are comprised of gas, which can be compressed – the result is less effective braking that becomes soft with more pedal travel.
Brake fluid should be changed every two years, but an easy visual check – a quick look inside the brake reservoir– can usually determine whether it's lost its effectiveness. Fresh brake fluid is clear or very light yellow. Fluid that is amber, brown or even black has broken down and is overdue for a change. The "dot" rating of brake fluid refers to its boiling point. For example, Dot 3 fluids for everyday use have a lower boiling point than a Dot 4 fluid recommended for performance driving.
Like engine oil, transmission fluid functions as a slippery lubricant for the moving parts inside your transmission. For automatic transmissions, the fluid serves double duty, working as a coolant and viscous hydraulic fluid that helps transfer the power from the engine. Each transmission has a recommended schedule found in the owner's manual – which varies whether it's an automatic or manual gearbox.
Although manual transmission fluid is not as prone to breakdown as motor oil, it suffers from contamination as the bearings, gears and syncros produce small metal filings. Automatic transmission fluids on the other hand, do break down and lose their lubricating ability. They also become contaminated with dirt and small metal pieces – which if not drained out, will contribute to the wear and tear on your transmission, therefore shortening its life.
It's important to regularly check the transmission's dipstick to ensure that it has the proper fluid level – an undetected leak can result in costly repairs, or transmission failure.
Power Steering Fluid
Like brake fluid, steering fluid is under pressure and powered by a hydraulic pump which makes turning the steering wheel easier. Over time, the fluid becomes contaminated by seals and o-rings breaking down, causing the pump to work harder, and eventually break down. Changing the fluid regularly is much more cost-effective than having to pay for a new power steering pump.