Boost Valve Kit Sonnax with Encapsulated Relief Valve 4L80E 4L85E

Sonnax Boost Valve Kit for 4L80-E, 4L85-E Vehicles equipped with GM 4L80-E and 4L85-E transmissions often face issues such as uncontrollable line rise (up to 500 psi), high line pressure in Reverse, and broken direct clutch drums or cases. These issues are typically caused by excessive EPC torque signal pressure. The Sonnax self-regulating boost valve kit 34200-10K addresses these problems by effectively limiting EPC pressure. Key Features: Hardened steel boost valve with an encapsulated relief valve that exhausts EPC pressure if it exceeds 95-105 psi Boost valve with over 20% wider spools for enhanced durability and increased sealing contact area Annular grooves on boost valve spools reduce side-loading and prevent wear Closely toleranced sleeve restores hydraulic integrity between the valve and sleeve O-Rings added to the sleeve ensure a positive seal, compensating for pump bore wear Drop-in Zip Valve™ parts for quick and easy installation Symptoms Addressed: Uncontrollable line r