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 104520-12K 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. A new pressure regulator valve outer spring is also included to replace weakened original springs and provides a modest 5 psi increase across the pressure curve.

Boost sleeve is manufactured from highly wear-resistant billet aluminum to prevent wear
Larger feed orifice provides quicker throttle response
Replacement spring provides modest 5psi line pressure increase
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, Exhaust, 30mm Head Dia, 0.274 in. Stem Dia, 4.587 Length, For Ford, Set of 8

MANLEY Valve, Race Master, Exhaust, 30mm Head Dia, 0.274 in. Stem Dia, 4.587 Length, For Ford, Set of 8

$408.60

MANLEY Valve, Race Master, Exhaust, 32.0 mm Head Dia, 6 mm Stem Dia, 94.0 mm Length, For Nissan VQ35, Set of 12

MANLEY Valve, Race Master, Exhaust, 32.0 mm Head Dia, 6 mm Stem Dia, 94.0 mm Length, For Nissan VQ35, Set of 12

$849.04

MANLEY Valve, Race Master, Exhaust, 29 mm Head Dia, 6 mm Stem Dia, 101.52 mm Length, For Mazda Miata, Each

MANLEY Valve, Race Master, Exhaust, 29 mm Head Dia, 6 mm Stem Dia, 101.52 mm Length, For Mazda Miata, Each

$49.91

MANLEY Valve, Pro Flo, Intake, 2.205 in. Head Dia, 0.3133 in. Stem Dia, 5.2 in. Length, For Chevrolet LS7, Each

MANLEY Valve, Pro Flo, Intake, 2.205 in. Head Dia, 0.3133 in. Stem Dia, 5.2 in. Length, For Chevrolet LS7, Each

$75.93

MANLEY Valve, Race Master, Intake, 2.08 in. Head Dia, 0.3415 in. Stem Dia, 5.34 in. Length, For Chevrolet SB, Each

MANLEY Valve, Race Master, Intake, 2.08 in. Head Dia, 0.3415 in. Stem Dia, 5.34 in. Length, For Chevrolet SB, Each

$47.58

MILODON Valves, Exhaust, Race, Stainless Steel, 1.625 in. Dia, +.200 Long, Small For Chevrolet, 350, 383, 400, Set of 8

MILODON Valves, Exhaust, Race, Stainless Steel, 1.625 in. Dia, +.200 Long, Small For Chevrolet, 350, 383, 400, Set of 8

$432.85