The process works because liquids are incompressible, and the density remains almost unchanged even during pressure and temperature rises. However, the fluid must retain its properties at all temperatures as it’s a lubricator for all movable parts in the braking system and prevents corrosion.
Another function the fluid performs is heat absorption. Braking generates heat, and it can cause moisture to condense in the brake system. At this point, the brake fluid acts as an absorbent that prevents water from boiling and causing brake failure.
Even though it’s crucial, regular car maintenance doesn’t usually include adding brake fluid. However, noticing a sudden drop in its level could be because your car brake pads have worn out, the system is acting up, or some components might require changing.
Knowing your car's braking system will enable you to choose the right one for your vehicle. But, as all brake fluids must always meet ISO and DOT (Department of Transportation) standards and are glycol-based, there are only so many to pick.
All in all, there’re four types of brake fluid on the market:
DOT 3, DOT 4, and DOT 5.1 are glycol-based fluids, while DOT 5 is silicone-based. The main difference is that DOT 3, DOT 4, and DOT 5.1 absorb water, while DOT 5 does not. But even though they’re distinguishable from each other, what matters is which type of fluid is compatible with the brake system.
When choosing the right type of fluid, you should consult the owner’s manual, which should contain the type of fluid you should use. Another way to do it is to simply check the master cylinder reservoir cap with the same information written on it.
After you’re done with that, all that’s left is to change the fluid. But to know just how much you should put in, determine the location of the reservoir and look at the fluid level marks, namely “full” and “add.” The first indicates the absolute max fluid level, while the latter implies you should top up when fluid is below it.
The idea here is simple: whenever the brake fluid is below “add,” you must pour in the brake fluid until it reaches the “full” mark, at which point you’ve put in just the right amount. Going over the maximum capacity or not topping up enough may cause additional problems with the brake system, so if you’re not confident you can handle it, simply delegate all this to a qualified mechanic.
As the brake system is hydraulic, it requires brake fluid to function correctly. If you want to change it yourself because the previous one got contaminated or there was an issue with the system, you must consult the owner's manual or reservoir cap containing the type needed. After that, you must look at the fluid level marks on the reservoir to ensure you’ll put in just enough.
But if you’re not confident you can handle fluid changing, you should drive to the nearest auto shop and ask for assistance. Even though it’ll cost you money, it’ll save you from further problems and allow you to retain peace of mind.
The 2027 Civic Type R goes on sale in October 2026, and it starts at $49,990, including the $1,295 destination charge.
Read the Full Article
Part of BMW’s Neue Klasse (new class) rollout of redesigned models, the 2027 BMW 3 Series is all-new and goes on sale in the first quarter of 2027.
Read the Full Article
Updates to the 2027 Honda Passport TrailSport include a reworked suspension, improved steering, subtle styling enhancements, and added standard equipment.
Read the Full Article
The midsize 2027 Mercedes GLE remains available in original and spicy Coupe recipes, now with standard 4Matic all-wheel drive (AWD), MBUX Superscreen technology, and a panoramic glass sunroof for ...See More
Read the Full Article