Changing Brake Fluid

Changing Brake Fluid

Changing brake fluid, general

When to change?
It is advisable to change the brake fluid every 45,000 km (28,000 miles) or every two years. If the brakes are used frequently and heavily, such as in mountainous areas or in a tropical climate with a high degree of humidity, the brake fluid must be changed every year.

Why change?
Brake fluid is hygroscopic, in other words it extracts water from the air. This happens, among other things, via the brake hoses and the brake fluid reservoir, which are made of rubber and plastic respectively and not completely resistant to water molecules.
A high water content greatly lowers the boiling point of the brake fluid and causes corrosion in the brake system.
This damages the brake system and braking operation is reduced.

Note: Use only original Volvo brake fluid with the (minimal) code DOT 4+. Never re-use brake fluid. Always store brake fluid in its original packaging, carefully closed.

Preparations
Use of a bleed system is recommended.
Take a collecting bottle with a transparent hose to collect the brake fluid.

Connecting bleed unit
Connect the bleed unit to the brake fluid reservoir.
Follow the manufacturers' instructions for connecting and using the unit.

Changing brake fluid





Remove the protective cap from the bleed nipple and connect the transparent hose to the collecting bottle. Open nipple about one turn.
Pressurize braking system with bleed unit.
Drain off 0.2-0.3 liters of brake fluid.
Close bleed nipple and remove hose.
Tightening torque: 5 Nm.
Install protective cap.
Fill the brake fluid reservoir slowly.
Slowly depress the brake pedal several times.

Changing order
Bleed/change in the following order:
- Rear right
- Rear left
- Front right
- Front left

Inspecting brake system after changing





Remove the bleed system.
Check whether there is still air in the system by depressing the brake pedal with a force equivalent to normal braking.
The pedal stroke should not exceed 40 mm with the engine turned off and after the brake pedal has been depressed 3-4 times. Bleed again if the pedal stroke exceeds 40 mm.
Check the brake system for leakage.
Check the brake fluid level.
Clean up the spilled brake fluid.