Symptoms:

  • Low line rise in Drive
  • Soft shifts
  • Burnt clutches

Cause:

Wear of the boost valve sleeve allows EPC fluid pressure escape to exhaust.

Correction:

Sonnax boost valve kit has upgraded materials and minimal clearances to prevent wear and restore proper hydraulic control.

6L45, 6L50, 6L80, 6L90

Boost Valve Kit
Part No. 104520-12K

You need this if... View Instructions Find a Distributor

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
  • Valve
  • Sleeve
  • Spring
  • 6L45, 6L50, 6L80, 6L90 Boost Valve Kit 104520-12K
  • 6L45, 6L50, 6L80, 6L90 Boost Valve Kit 104520-12K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

6L45, 6L50, 6L80, 6L90 Boost Valve Kit Vacuum Test Locations