TM10-3930-660-20 12-7. SERVICE  BRAKE  CONTROL VALVE -  REPLACE/ADJUST (Cont ‘d) ADJUST  ACCUMULATOR  CHARGING  PRESSURE The accumulator charging pressure is adjusted at the brake control valve. 1.   PUMP THE BRAKE PEDAL TO RELIEVE PRESSURE IN ACCUMULATOR (23). With the engine stopped, pump the brake pedal until no power assistance is felt through the pedal. This will require approximately 20 depressions of the brake pedal. DISCONNECT HOSE (7) AND ELBOW (8) AT SERVICE BRAKE CONTROL VALVE (6). INSTALL PRESSURE GAUGE TO ACCUMULATOR PORT (a) ON SERVICE BRAKE CONTROL VALVE  (6). Note pressure gauge reading when click is 4. 5. heard in step 4. START ENGINE AND LISTEN FOR CLICK CAUSED BY SHIFTING OF THE ACCUMULATOR CHARGING VALVE INSIDE SERVICE BRAKE CONTROL VALVE (6). IF NECESSARY, ADJUST ACCUMULATOR CHARGING PRESSURE. a. If pressure is less than 1650 +/- 25 psi at time click is heard, turn adjusting plug (b) on valve (6) clockwise until pressure is within specifications. 6. b. If pressure is greater than 1650 +/- 25 psi at time the click is heard, turn adjusting 7. plug (b) on valve (6) counterclockwise  until  pressure is within specifications. 8. REMOVE PRESSURE GAUGE FROM ACCUMULATOR PORT (a) ON SERVICE BRAKE CONTROL VALVE (6). CONNECT ELBOW (8) AND HOSE (7) AT SERVICE BRAKE CONTROL VALVE (6). BLEED THE BRAKE SYSTEM, PARA. 12-5. 12-21