Continuous movement of the pressure regulator valve wears the valve body bore in Aisin AW 450-43LE units. Bore and/or valve wear causes erratic line pressure, resulting in delayed engagements, loss of lockup and high or low line pressure, depending on the area and extent of wear.
The boost assembly is designed to increase line pressure in Drive and Reverse. When the sleeve is worn on the inside, boost or EPC fluids can leak to exhaust or cross leak and increase forces on the valve. Leakage to exhaust reduces line rise. Cross leaks can result in broken clutch drums or cases. The Sonnax oversized PR valve, boost valve and sleeve kit 94987-11K restores hydraulic control to these circuits.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
A vacuum test at the port indicated fails to hold at least 14 in-Hg.