Vehicles with Mazda F4A-EL, F4EAT or GF4A-EL transmissions may have problems with low line rise or low Reverse boost. These problems can be caused by worn boost valve sleeves that allow EPC, TV boost or Reverse pressures to cross-leak or leak to exhaust. Sonnax boost valve kit 74846-01K restores hydraulic integrity.

• Hardcoat anodized aluminum valve combats premature wear
• Sleeve manufactured from high quality aluminum resists wear