• Low line rise
  • Low line rise in Reverse & shudder
  • 1-2 Quality poor
  • Delayed Reverse


Worn boost valve sleeves allow EPC, TV boost or reverse pressures to cross leak into exhaust.


These replacement boost valve kits are hardened and anodized to prevent wear and are tightly toleranced to restore the hydraulic integrity of the circuits.


The applications listed above are meant as a guide only. Be sure to measure original valve and compare dimensions before purchasing.


Boost Valve Kit
Part No. 74846-01K

No TV cable, electronic transmissions, Factory style sleeve, no o-rings

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Vehicles with a G4A-EL or GF4A-EL, F4A-EL, or F4EAT transmission may have problems with low line rise or low reverse boost. These problems can be caused by worn boost valve sleeves that allow EPC (GF4A-EL F4A-EL, F4EAT), TV boost (G4A-EL F4A-EL, F4EAT), or reverse pressures to cross leak or leak to exhaust. Sonnax has developed replacement boost valve kits for both the G4A-EL, [71846-01K] and the GF4A-EL, F4A-EL, and F4EAT 74846-01K.

  • The GF4A-EL boost valve is made from anodized aluminum, and the sleeve is manufactured from high-quality aluminum to resist wear.
  • The 74846-01K GF4A-EL kit has been modified to fit the F4A-EL and F4EAT applications, and allows for more responsive EPC pressure.

No TV Cable/with Electronic Transmission

  • Valve
  • Sleeve
  • F4A-EL, F4EAT, GF4A-EL Boost Valve Kit 74846-01K
  • F4A-EL, F4EAT, GF4A-EL Boost Valve Kit 74846-01K