August 21, 2013
Vehicles with listed GM transmissions may exhibit insufficient line rise in drive ranges, soft shifts and/or burnt clutches. These problems may be caused by continuous oscillation of the boost valve within the boost sleeve, creating excessive wear and a path for EPC fluid pressure to leak to exhaust. Sonnax boost valve kit 104520-01K has upgraded materials and minimal clearances to prevent wear and restore proper hydraulic control. The sleeve also has a slightly larger EPC feed orifice to provide quicker throttle response.
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.