Hydraulic Control System

HYDRAULIC CONTROL SYSTEM

DESCRIPTION





Better and smoother shift quality.
In order to prevent ATF leakage from the valve body or each elements, the exhaust ports have been grouped into only one with an addition of a check ball.
If a fail occurs in its electric control, the switch valve and fail safe valve is able to move to enable 3rd speed drive or reverse.
The hydraulic system consists of oil pump, regulator valve, solenoid valves, pressure control valve and valve body.

OPERATION COMPONENTS AND FUNCTIONS
Oil Pump
The oil pump is made of aluminum to reduce its weight. The oil pump is not serviceable part; it must be replaced as a pump assembly.
Do not disassemble the pump as improper alignment during assembly will cause pump failure and could cause damage to the transaxle.
When removing the oil pump from the T/M case, the S.S.T. (09452-33100) must be used.

Valve Body
To prevent damage to transaxle components make sure that the manual control lever and the park / neutral switch have been removed before attempting to remove the valve body.
Be careful not to lose two steel balls on the valve body when removing and installing the valve body.
The valve body mounting bolts are different lengths. Note the locations of the bolts to aid in assembly.

OPERATION OF EACH VALVE
Torque converter pressure control valve: The function of this valve is to maintain a constant pressure within the torque converter.
Damper clutch control valve: Its function is to control the hydraulic pressure that acts on the Damper Clutch. Manual valve. The position of the manual valve is determined by the selector lever and applies or cuts line pressure to different valves.
Pressure control valve & Solenoid valve: The pressure control valve prevents a rapid decrease in hydraulic pressure when the clutch becomes disengaged. It also reduces the sharp increase in input shaft speed during clutch to clutch control.
Switch valve: When the OD clutch is applied, the hydraulic pressure is applied to the regulator valve via the switch valve. Hence, the line pressure is reduced at 3rd and 4th gear.
Fail Safe Valve-A: During fail safe mode, this valve releases the pressure in the LR Brake.
Fail Safe Valve-B: During fail safe mode, this valve cuts the pressure from the 2ndpressure control valve to 2nd brake.

HYDRAULIC FLOW
Fluid Diagrams