In Toyota/Lexus A340E and A340F late-style units the OE steel Reverse, EPC and cutback boost valves wear the inside diameters of the cast aluminum boost sleeve due to continuous reciprocation as they provide biasing force to adjust main line pressure. This wear allows critical Reverse, EPC and cutback fluid pressures to leak or cross-leak, creating numerous drivability complaints and part failures.
Replacing the OE assembly requires matching the correct valve spool ratio (three-dot, two-dot or no-dot sleeve) to ensure proper line pressure. The Sonnax dual-ratio boost valve kit 97741-01K not only restores hydraulic integrity, but also provides for all OE ratios in one assembly. By selecting either the large diameter priority or small diameter priority EPC boost valve and adding optional shims to the OE pressure regulator valve spring face, all three of the OE ratios can be achieved with the one assembly.

Sleeve is made from high-quality aluminum for wear resistance
Hardcoat anodized aluminum valves combat premature wear
Unique priority diameter design allows for dual-ratio in one assembly
Additional shims allow for tuning to the third OE ratio
Drop-in Zip Valve™ parts install quickly and easily

Learn More About Zip Valve™ Drop-In Repairs

More From This Category

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.6 in. Head Dia, 0.3415 in. Stem Dia, 5.26 in. Height, Set of 8

MANLEY Valve, Titanium, Exhaust, Bead Loc, 1.6 in. Head Dia, 0.3415 in. Stem Dia, 5.26 in. Height, Set of 8

$2,461.66

MANLEY Valve, Pro Flo, Intake, 2.055 in. Head Dia, 0.3415 in. Stem Dia, 5.011 in. Length, Set of 8

MANLEY Valve, Pro Flo, Intake, 2.055 in. Head Dia, 0.3415 in. Stem Dia, 5.011 in. Length, Set of 8

$607.34

MANLEY Valve, Titanium, Intake, Bead Loc, 2.5 in. Head Dia, 0.3415 in. Stem Dia, 6.4 in. Length, Set of 8

MANLEY Valve, Titanium, Intake, Bead Loc, 2.5 in. Head Dia, 0.3415 in. Stem Dia, 6.4 in. Length, Set of 8

$2,591.35

MANLEY Valve, Race Flo, Intake, 2.12 in. Head Dia, 0.3133 in. Stem Dia, 5.253 in. Length, For Chevrolet LT1, Each

MANLEY Valve, Race Flo, Intake, 2.12 in. Head Dia, 0.3133 in. Stem Dia, 5.253 in. Length, For Chevrolet LT1, Each

$47.58

Sonnax K3 Clutch Control Valve Kit, Aisin Aw, Aw Tr-60Sn, 09D, Each

Sonnax K3 Clutch Control Valve Kit, Aisin Aw, Aw Tr-60Sn, 09D, Each

$116.53

Sonnax Oversized Clutch Boost/Latch Valve, Ford, 6F50/55, 6T70/75 Gen I, Each

Sonnax Oversized Clutch Boost/Latch Valve, Ford, 6F50/55, 6T70/75 Gen I, Each

$91.01