Johnsons-Mechanic-Rockhampton

Blog

Posted in

Brake Fluid | Preventative Maintenance

Preventative maintenance is essential in ensuring you see the best value and life out of a vehicle. One of the critical items is brake fluid. Following the manufacturer’s guidelines and maintenance schedule recommendations will enable safety and reliability. 

When it comes to Brake Fluid, this item should be checked and replaced/flushed when the logbook suggests it. Most recommendations are to change the fluid every two years, regardless of if you have travelled the allocated kilometres or not. 

To the everyday person, this begs the question, why do we need to change our brake fluid at all? 

Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications. It transfers force into pressure and amplifies braking force. It works because liquids are not substantially compressible, and the brake fluid must also resist, as much as possible, the high temperatures created by the braking forces. 

When brake fluid absorbs enough heat, it boils and vaporises and turns from a fluid into a gas. This gas can lead to complete brake failure in hydraulic systems. Suddenly the incompressible nature of the brake fluid, which produces the firm lever feel that we know and trust has disappeared due to the introduction of compressible gasses in the brake system. Brake fluid is hygroscopic, and this means it absorbs moisture. Moisture from the atmosphere and moisture from the gas transferred up the lines.

Therefore, any moisture in the brake fluid will reduce the boiling point and affect your vehicle’s braking performance and the seals of the components that may cause leakage or internal bypassing (that foot goes to floor feeling).  

One other item about your brake fluid is the level. The brake fluid reservoir has a maximum and a minimum mark. If your fluid is in between these marks, everything is ok. Most late-model vehicles are fitted with a level switch that will activate when the level gets low. The reason your fluid level would get low is the brake material on your pads/linings is wearing away. When you experience the brake light staying on your dash, that is an indicator to contact your service centre and have them investigate. 

If you don’t feel your brakes are performing as they should be, please reach out to us by calling, walking in or booking online.