Product Description
Boost Valve Kit
Part No. 34200-01K
O-Ring style. Kit can be retrofit to back to '89 units. See instructions for details.
Common problems in vehicles with GM 4L80-E and 4L85-E transmissions are uncontrollable line rise (upward of 500-600 psi), high line pressure in Reverse, buzzing noise, broken direct clutch drums and/or broken cases. These problems are usually caused by reverse boost oil that enters the torque signal circuit due to a wear-created cross leak at the sleeve. High line pressure and buzz is created by oil leakage past the aluminum balance plug. The Sonnax boost valve kit 34200-01K eliminates these problems.
- Hardened steel boost valve has 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
- Quality steel boost sleeve with external O-rings provides positive seal to compensate for pump cover bore wear
- Kit includes a replacement aluminum balance oil plug with an O-ring to ensure proper sealing and adequate back pressure on the pressure regulator valve
- Valve
- Sleeve
- Sleeve O-Rings (2)
- Balance Plug
- Balance Plug O-Ring
Symptoms:
- Uncontrollable line rise
- High line pressure
- Broken parts
- Broken clutch piston
Cause:
Worn boost valve sleeve allows reverse oil leakage and worn end plug causes imbalance of the pressure regulator valve.
Correction:
Ensure proper regulator valve control with this O-ringed balance oil plug and boost valve & sleeve kit that replaces either the 1997-later or 1996-earlier OE boost valve designs.
