Common problems in vehicles with GM 4L80-E and 4L85-E transmissions 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. Sonnax self-regulating boost valve kit 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
Drop-in Zip Valve™ parts install quickly and easily

Learn More About Zip Valve™ Drop-In Repairs

More From This Category

MANLEY Valve, Race Master, For Toyota 3UR-FE, 38mm Head Dia, Each

MANLEY Valve, Race Master, For Toyota 3UR-FE, 38mm Head Dia, Each

$48.92

MANLEY Valve, Race Flo, Intake, Bead Loc, 2.02 in. Head Dia, 0.3125 in. Stem Dia, 4.955 in. Length, For Chrysler HEMI, Each

MANLEY Valve, Race Flo, Intake, Bead Loc, 2.02 in. Head Dia, 0.3125 in. Stem Dia, 4.955 in. Length, For Chrysler HEMI, Each

$142.29

Sonnax Oversized Pressure Regulator Valve, ZF5Hp19, Late Vb E18.2, Each

Sonnax Oversized Pressure Regulator Valve, ZF5Hp19, Late Vb E18.2, Each

$74.75

Trick Flow Valve, Exhaust, Stainless Steel, 1.760 in. Diameter, .341 in. Stem, 5.060 in. Length, Big For Ford, Each

Trick Flow Valve, Exhaust, Stainless Steel, 1.760 in. Diameter, .341 in. Stem, 5.060 in. Length, Big For Ford, Each

$76.10

MILODON Valves, Intake, Race, Stainless Steel, 2.30 in. Dia, +.350 Long, Big For Chevrolet, 396, 427, 454, 502, Each

MILODON Valves, Intake, Race, Stainless Steel, 2.30 in. Dia, +.350 Long, Big For Chevrolet, 396, 427, 454, 502, Each

$79.09

Sonnax Oversized Tc Pressure Valve Kit, Chrysler, Ch 845Re, ZF8Hp/45/55/70, Each

Sonnax Oversized Tc Pressure Valve Kit, Chrysler, Ch 845Re, ZF8Hp/45/55/70, Each

$37.73