December 09, 2013
Vehicles with Toyota/Lexus U660E and U660F transmissions may exhibit 2nd and 6th Gear shift complaints and a burned B1 brake. These problems may be caused by continuous oscillation of the steel B1 apply boost valve within the cast aluminum boost sleeve, creating excessive wear and a path for line pressure to exhaust and the B1 apply control valve to stroke prematurely.
Sonnax B1 apply boost valve kit 47740-19K has upgraded materials and minimal clearances to prevent wear and restore proper hydraulic control.
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.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.