Bleeding The Main Brake Valve For Trailers - Zetor PROXIMA POWER Z90 2012 Operator's Manual

1. BLEEDING THE MAIN BRAKE VALVE FOR TRAILERS

Perform the bleeding at the operation pressure of air in the system of 730±20 kPa in
the following way:
1. Fill up the missing volume of brake liquid in the equalizing tank to the maximum
quantity.
2. Remove the caps from the bleeding screws (2) of the trailer control valve (1) situ-
ated at the right side of the tractor between the tank and the rear half-axle.
3. Slide hoses onto the screws and immerse their other ends to the bottom of a
transparent container (3) partly filled with the brake liquid. Place the container at
least 300 mm above the bleeding screws. The screws must be permanently under
pressure to avoid aeration of the brake system through their threads.
4. Release the bleeding screws by 1/4 turn at the most.
5. The bleeding procedure is the same as described in the Note (see page 188).
6. Completely depress the pedal that is not blocked with the gauge and tighten the
bleeding screw.
7. Release the brake pedal and repeat the procedure until air bubbles stop escaping
from the hose.
ADJUSTMENT
190
E758