The actuator feed limit (AFL) valve in GM 8L45 and 8L90 transmissions functions to regulate the line pressure to other areas of the system including the converter. When the pressure exceeds the limit set by the valve and spring, the valve moves to limit the fluid through the circuit to keep the pressure at the desired level.
Excessive wear in the AFL valve bore allows pressure loss and/or malfunctioning valve cycles that causes drivability concerns. The resulting low regulated pressure from leakage can cause low clutch pressure and transmission slips or harsh shifts.
Installing Sonnax actuator feed limit valve kit 154740-35K restores proper hydraulic integrity of the circuit.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.