VALVE, 4L80E BOOST VALVE 1991-UP (SELF REGULATING WITH O-RINGS)4L80E, 4L85E
Boost Valve Kit
Part No. 34200-10K
- O-Rings (2)
With built-in relief
Common problems in vehicles with a 4L80E transmission include uncontrollable line rise (upward of 500 psi), high line pressure in reverse, broken direct clutch drums and/or broken cases. These problems can be caused by excessive EPC torque signal pressure. The Sonnax self-regulating reverse boost valve 34200-10K eliminates these problems by limiting EPC pressure.
- Hardened steel boost valve has an encapsulated relief valve that will allow EPC pressure to exhaust if it exceeds 95-105 psi.
- Boost valve with over 20% wider spools to provide better durability and increased sealing contact area.
- Boost valve spools have annular grooves to reduce side loading that causes wear.
- Closely toleranced sleeve restores the hydraulic integrity between the valve and sleeve.
- O-rings have been added to the sleeve to provide a positive seal that compensates for pump bore wear.
NOTE: Kit includes instructions to retrofit parts dating back to 1989.