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

Trick Flow Valve, Exhaust, Stainless Steel, 1.600 in. Diameter, .341 in. Stem, 4.980 in. Length, For Chevrolet, For Ford, Each

Trick Flow Valve, Exhaust, Stainless Steel, 1.600 in. Diameter, .341 in. Stem, 4.980 in. Length, For Chevrolet, For Ford, Each

$48.74

MANLEY Valve, Race Master, Exhaust, 1.6 in. Head Dia., 0.3136 in. Stem Dia., 4.923 in. Length, For Chevrolet LS1, Set of 8

MANLEY Valve, Race Master, Exhaust, 1.6 in. Head Dia., 0.3136 in. Stem Dia., 4.923 in. Length, For Chevrolet LS1, Set of 8

$275.90

MANLEY Valve, Custom, Titanium, .3135 in. Stem Dia., Set of 8

MANLEY Valve, Custom, Titanium, .3135 in. Stem Dia., Set of 8

$1,649.72

MANLEY Valve, Extreme/Severe Duty, Exhaust, 2 in. Head Dia., 0.3415 in. Stem Dia., 6.7 in. Length, Gen II, Set of 8

MANLEY Valve, Extreme/Severe Duty, Exhaust, 2 in. Head Dia., 0.3415 in. Stem Dia., 6.7 in. Length, Gen II, Set of 8

$505.41

MANLEY Valve, Race Master, Intake, Bead Loc, 44.5mm Head Dia., 0.275 in. Stem Dia., 4.705 Length, For Ford, Each

MANLEY Valve, Race Master, Intake, Bead Loc, 44.5mm Head Dia., 0.275 in. Stem Dia., 4.705 Length, For Ford, Each

$37.02

MANLEY Valve, Race Master, Intake, Bead Loc, 34mm Head Dia., 0.2355 in. Stem Dia., 4.62 Length, For Ford, Each

MANLEY Valve, Race Master, Intake, Bead Loc, 34mm Head Dia., 0.2355 in. Stem Dia., 4.62 Length, For Ford, Each

$37.02