6.6.7. Replacement of brake fluid
It is recommended to change brake fluid after 45 000 km of a run or every two years. If brakes are used with big loading, for example, when driving in the hilly area, and also in the conditions of tropical climate at high humidity, it is necessary to change brake fluid once a year. Brake fluid is hygroscopic, i.e. it has property to absorb water molecules from air. Absorption happens through the brake hoses and a tank of brake fluid made respectively of rubber and plastic, which somewhat pronitsayema for air molecules. Increase in content of water in brake fluid leads to considerable decrease in temperature of boiling of brake fluid, and also to corrosion of elements of the brake system. It is resulted by damage of the brake system, and its functioning considerably worsens.
It is possible to use only the original Volvo brake fluid with marking of DOT 4+ (minimum). It is impossible to reuse old brake fluid. Brake fluid has to be stored only in the original packing which is hermetically closed.
Preparation for replacement of liquid is similar to preparation for pumping of the brake system. Further it is necessary to work in such order:
— remove a protective cap from the drain union and connect to it a transparent hose of drain capacity;
— unscrew the union approximately on one turn;
— lift pressure in the brake system by means of the special device;
— merge 0,2 — 0,2 l of brake fluid;
— close the drain union and disconnect a hose;
— put a protective cap.
Carry out pumping and replacement of liquid in the following order:
— right back wheel;
— left back wheel;
— right forward wheel;
— left forward wheel.
After replacement of brake fluid check of the brake system is obligatory.