THEORY OF OPERATION - CONTINUED
BRAKE AND HYDRAULIC FAN SYSTEM - CONTINUED
When brake pedal is released, oil behind piston flows through an oil passage in differential housing to ser-
vice brake control valve, then returns to hydraulic oil tank. With no oil pressure behind piston, springs
move piston to RETRACTED position and service brakes are released.
Service brakes can be actuated by either left or right brake pedal. When transmission neutralizer is dis-
abled, both brake pedals apply service brakes; however, only left pedal may be used to neutralize transmis-
sion. This allows full engine power to be used in hydraulic system.
If machine loses power or if hydraulic pump fails, service brakes can still be applied. Pressure in nitrogen-
charged service brake accumulators allows several applications of brake pedals. This is for stopping or
slowing machine enough to engage parking brake.
Service Brake Wear Indicator.