Brake fluid reservoir in a car.
When it comes to car maintenance, servicing and oil changes are the topics that get the most attention. In particular, motorists have plenty of questions to ask about oil change intervals.
So, it is time we gave the braking system the attention it also deserves!
WHAT DOES THE FLUID DO?
A car brakes are operated by hydraulic systems and hence require brake fluid. The exceptions are some vintage cars, which use braking systems operated by rods and linkages.
In the future, brake-by-wire might even be implemented in cars.
The hydraulic circuit in a car’s braking system is a closed type. That means the brake fluid never gets consumed and the total volume is always constant.
IF THIS IS TRUE, WHY DO WE NEED TO TOP-UP BRAKE FLUID?
A low brake fluid level warning is usually triggered by worn brake pads. When the brake pads thin out after prolonged use, more fluid is required in the piston chambers to maintain the pads’ contact with the disc.
This is also why when brake pads are worn, the brake pedal must travel further before the brakes “bite”.
Braking with worn pads leads lead to a drop in the level within the brake fluid reservoir.
SOLUTIONS TO THE LOW FLUID LEVEL
The best solution is to replace the worn pads with new ones. The thicker pads will push the pistons back into the chamber, forcing brake fluid to return to the reservoir.
But another cause for a depleting reservoir is a leak within the braking system. If you suspect one, immediately have your car checked by a qualified mechanic.
THE FLUID EVENTUALLY HAS TO BE REPLACED
Now, even without a leak, hydraulic fluid degrades over time. So it must be replaced.
The fluid needs to be pumped out and replaced with fresh fluid. Then the system needs to be bled to expel air bubbles.
Have this done at a workshop roughly every 60,000km.
