2001-2003 Honda TRX500FA Factory Service Manual, Page 398Get this manual
TECHNICAL FEATURES COMPRESSION BRAKING AND PRESSURE CONTROL ehetic Valves and Pressure Control Valves-D uri ng normal running, the check va lve in the pump-side cylinder feeds hydraulic flu id into the low- pressure ircuitThe check alv is open when the hydraulic pressure in the low-pressure circuit dr ops below specified leve andupon ad'l ieving the proper pressure, closes to prevent badc.flowUnder engine compression brak ing conditions (where the rotational force co es from the wheels), the motor side becomes pump (dr iv en by the pumpmotor shaft) and the pump side becomes hydraulic motorIn this situation, the ig h- and low-pressu re circuits in the automatic transmissio nit are reversedT his transmission uses separate check va lve feed hydraulic fluid to he engine braking low-pressu re ci rcuitPressure co ntrol valves vent excessive high-pressure fluid into the low-pressu re ci rcuit during both normal runn in an co mpression braking conditions