180
ADJUSTMENT 
 C759   
3. BLEEDING OF HYDRAULIC BRAKES OF TRAILER 
Bleed the system in the following way: 
-  Add missing volume of brake fluid into the equalising tank up to maximum level. 
-  Remove plug of vent screw (2) of hydraulic trailer control valve (1) located at the 
left-hand front support of the cab silent-block. 
- Slide a hose on the screw and put the hose other end at the bottom of a 
transparent tank (3) partially filled with brake fluid. Place the tank 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 maximum by 1/4 turn.  
- Fully depress the latched brake pedals to the stop and tighten the adjusting 
screws.  
-  Release the brake pedals and repeat the process, until air bubbles cease escaping 
from the hose.