TM 10-3930-664-24 4-6.  TRANSMISSION CHECKS. a. Transmission Pressure Check.  Transmission problems can be isolated by the use of pressure checks.  When the stall check indicates a slipping clutch, measure clutch pack pressure to determine if the slippage is due to low pressure or clutch plate friction material failure.  In addition, converter charging pressure and transmission lubrication pressure may also be measured. b. Transmission  Mechanical  Check.    Prior  to  checking  any  part  of  the  system  for  hydraulic  friction  (pressure checking), the following mechanical checks must be performed: (1) Check mechanical inching from brake pedal to inching valve on transmission. (2) Check linkage from axle disconnect to disconnect actuator. (3) Check parking brake and inching pedal for correct adjustment and travel.  Be sure the pedal moves freely and returns fully. (4) Check that all linkages are properly connected and adjusted in each segment and at all connecting points. (5) Check wiring and electrical control components for obvious damage. (6) Check that cooling system is in good working order.  Radiator fins must be clean to maintain proper cooling and operating temperatures. (7) The engine must be fully operational to perform pressure checks. c. Transmission Hydraulic Check.  Before checking the transmission clutches, torque converter, charging pump, and hydraulic circuits for pressure and rate of flow, it is important to make the following checks: (1) Check oil level in the transmission.  The transmission fluid must be at the correct (full) level. (2) All clutches, converter, and fluid lines must be fully charged (filled) at all times during pressure checks. CAUTION The transmission fluid must be at operating temperature of 180-200OF (82-930C) to obtain correct fluid level and pressure readings.  Do not attempt to make these checks with cold oil. (3) To  raise  the  oil  temperature  to  180-200OF  (82-930C),  operate  (work)  the  vehicle  or  perform  the  STALL CHECK. 4-3