A750E, A750F, TB-50LS

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:
These complaints can be caused by severe wear of the boost valve sleeve, allowing EPC, cutback and reverse oil leakage.

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

Toyota/Lexus vehicles with A750, A760, A960 and AB60 series 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. The Sonnax boost valve kit 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
• Restores proper line rise

Content:

• Inner Boost Valve
• Outer Boost Valve
• Sleeve

SONNAX Installation Instructions