6.6.6. Pumping of the brake system
At repair or replacement of one support usually there is enough its individual pumping. If during performance of work the pedal of a brake was in the squeezed-out situation, brake fluid does not follow from system.
For the brake system it is possible to use only the original Volvo brake fluid with marking of DOT 4+ (minimum). It is impossible to use old brake fluid.
After repair of a support its individual pumping suffices, and after replacement of the main cylinder or the ABS block pumping of all system is carried out.
Brake fluid has to be stored only in the original packing which is hermetically closed.
By preparation for pumping:
— switch off ignition;
— clear a tank cover for brake fluid and an adjacent surface;
Pumping of system can be carried out as a usual way, and by means of the special device creating excessive pressure.
When pumping system by means of the special device creating excessive pressure it is necessary to follow the instruction of manufacturer for operation of such device. Pumping of the brake system without the special equipment needs to be carried out at the idle engine with the assistant and in such sequence:
— clear valves of pumping of wheel brake mechanisms of dirt and remove from them protective caps;
Fig. 6.16. Pumping of the brake system
— install on the valve of pumping of the right back brake mechanism a transparent hose (fig. 6.16)
the second end of which lower in the capacity which is partially filled with brake fluid, so that the end of a hose plunged into liquid;
— check the level of brake fluid in a tank of the main brake cylinder and bring it to the mark max. Further when pumping constantly control the level of brake fluid and add it, without allowing falling of level tags of "min" are lower;
— press several times a brake pedal to remove vials of air from the main brake cylinder;
— unscrew the valve of pumping of the right back brake mechanism on 3/4 turns and make 4 — 5 musclemen by a brake pedal. In the liquid following from a hose vials of air will be visible. On the fifth muscleman press a pedal against the stop and you hold, do not wrap the pumping valve yet, then release a pedal;
— check the level of brake fluid in a tank of the main brake cylinder and if it is necessary, add liquid;
— repeat pumping until an exit of vials of air from a transparent hose completely does not stop.
Check the brake system after pumping:
— remove the equipment for pumping;
— check existence of the remains of air in system, pressing a brake pedal as at normal braking. After 3 — 4-fold pressing a brake pedal at the switched-off engine its course should not exceed 40 mm. If the course of a pedal exceeds 40 mm, repeat pumping;
— check whether there are no leaks from the brake system;
— check the level of brake fluid in a tank, wipe the spilled brake fluid.