Bleeding Of Hydraulic Trailer Brake System - Zetor 3321 SUPER Operator's Manual

Check the brake fluid level in the brake
fluid reservoir (1) when bleeding to avoid
aerating of the brake system. Keep the
hose end permanently under brake fluid
level. Reservoir (3) needs to be kept in
the highest possible position. The brake
fluid must be completely exchanged in
the whole brake circuit minimally after
two years.
ADJUSTMENT
Dop 7

2. BLEEDING OF HYDRAULIC TRAILER BRAKE SYSTEM

Bleed the system following the instructions:
- Add the missing volume of brake fluid into the brake fluid reservoir up to max.
level.
- Remove plugs from vent screws (2) of hydraulic trailer control valve (3) located on
the left cab silentblock support.
- Slide the hose on the vent screw and put the other end of hose into the
transparent reservoir (4) partially filled with brake fluid. Place the reservoir
minimally 300 mm above the vent screw. The vent screw must be permanently
under pressure to avoid aerating of brake system through the screw threads.
- Loosen the bleeding screws max. by 1/4 turns.
- Test which pedal causes flowing the fluid into tank after pressing pedal. You will do
bleeding by this pedal.
- Process for bleeding is the same as mentioned in - Important (see page 156).
- Fully press the pedal which is not blocked by gauge and tighten the adjusting
screw.
- Release the brake pedal and repeat the process so long until bubbles come from
the hose.
157
Dop 8