December 09, 2013
Vehicles with Toyota/Lexus U660E, 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.
A vacuum test at the port indicated fails to hold at least 18 in-Hg.