1-2 Shift Valve

During 1st gear, the shift solenoid valve # 2 is turned OFF which directs line pressure to one of the passages of the 1-2 shift valve. The 1-2 shift valve is pushed by line pressure and shut off line pressure to the second brake. This way, the second brake is released.

During 2nd gear, the shift solenoid valve # 2 is turned ON. Line pressure to one of the passages of the 1-2 shift valve is exhausted. Spring force moves the valve to open position, sending line pressure passage to the second brake, thus applying it.

When the manual selector is moved to Second (2) position, the manual shift valve sends line pressure to another passage of the 1-2 shift valve. Line pressure is then directed to the second coast brake (going through the intermediate modulator valve), and applies the second coast brake.

When the manual selector is moved to Low (L) position, the manual shift valve sends line pressure to yet another passage of the 1-2 shift valve. Line pressure is then directed to the reverse brake, thus applying it.