Suncoast Converters Boost Valve Kit - Early Style .490 Dia. O-ring Style 77898E-K

The Sun Coast Converters boost valve kit is an early-style, .490-inch diameter, O-ring style assembly designed to restore hydraulic integrity and prevent leakage in early-style pumps.

This kit addresses common issues in GM 4L60-E and 4L65-E transmissions such as poor line rise, leading to 3-4 clutch or 2-4 band failure, and poor shift quality. These problems often stem from a worn boost sleeve, causing oil leakage and reduced pressure rise.

The kit includes a sleeve, two O-rings, and a .490-inch diameter valve with no groove. Installing this Sonnax boost valve kit is presented as a correction to worn boost sleeves and subsequent cross-leakage or leakage to the sump.