Sonnax Oversized Pressure Regulator Boost Valve Kit

The Sonnax Oversized Pressure Regulator & Boost Valve Kit line restores hydraulic control in automatic transmission valve bodies. Over time, the original pressure regulator valve bore and the boost valve and sleeve wear. That wear lets line pressure leak away, which can cause soft or harsh shifts, low or erratic line pressure, high pressure in Reverse, overheating and burned clutches or bands. These kits are used to rebuild or recondition the worn bore and bring back correct valve-to-bore clearances.

Key Features:

• Oversized pressure regulator valve restores tight clearances in a worn bore, so the valve can hold correct line pressure.
• Replacement boost valve and sleeve assembly is matched to the oversized regulator valve. It helps restore proper line rise and Reverse pressure.
• Hardcoat anodized aluminum valves resist premature wear.
• Upgraded materials and tight tolerances help maintain consistent hydraulic control.
• Application-specific engineering is used in many kits. Examples include annular grooves that reduce side-loading wear and revised reaction-area ratios for firmer shifts.

Installation Notes: Installing an oversized valve requires reaming the valve body bore. Sonnax offers matching reaming tool kits for this, and some applications also use a bore sizing tool or the VB-FIX fixture. These are sold separately. The oversized boost valve and sleeve supplied in the kit must be used together with the oversized regulator valve.

Sonnax is a well-known name in transmission valve body repair. These kits give rebuilders a lasting fix for a common source of pressure-control problems and help restore shift quality and transmission reliability.