Symptoms:

  • Clutch failure
  • Soft shifts
  • Harsh shifts
  • High line pressure in Reverse
  • Low line rise in Drive
  • High line pressure
  • Low line pressure
  • Overheating
  • Low converter pressure

Cause:

Severe wear of the boost valve sleeve, allows EPC, cutback and Reverse oil leakage.

Correction:

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

A750E, A750F, A760E, A760F, A760H, A761E, A960E, A960F, AB60E, AB60F

Boost Valve Kit
Part No. 147741-01K

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

Vehicles with Toyota/Lexus A750E/F, A760E/F/H, A761E, A960E/F and AB60E/F transmissions may exhibit insufficient line rise in drive ranges and excessively high pressures in Reverse. This may be caused by continuous oscillation of the steel boost valves within the cast aluminum sleeve, creating excessive wear and a path for EPC, cutback and Reverse pressure to leak.

Severe wear at the Reverse circuit allows line pressure to cross-leak to the EPC circuit, causing abnormally high pressures. Wear in the cutback circuit allows fluid to cross-leak into an exhaust circuit, causing low line pressure resulting in soft shifts and band failures. Sonnax boost valve kit 147741-01K has upgraded materials and minimal clearances to prevent wear and restore proper hydraulic control.

  • Boost sleeve is manufactured from highly wear-resistant billet aluminum to prevent the excessive wear exhibited by the cast OE sleeve
  • Hardcoat anodized aluminum valves combat premature wear
  • Restores proper line rise
  • Inner Boost Valve
  • Outer Boost Valve
  • Sleeve

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Toyota A760E/F/H Series Valve Body Layout

Toyota A760E/F/H Series Valve Body Layout

Toyota/Lexus A750E/F Valve Body Layout

Toyota/Lexus A750E/F Valve Body Layout
  • A750E, A750F, A760E, A760F, A760H, A761E, A960E, A960F, AB60E, AB60F Boost Valve Kit 147741-01K
  • A750E, A750F, A760E, A760F, A760H, A761E, A960E, A960F, AB60E, AB60F Boost Valve Kit 147741-01K

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.

A750E, A750F, A760E, A760F, A760H, A761E, A960E, A960F, AB60E, AB60F Boost Valve Kit Vacuum Test Locations