The B1 brake in Aisin AW 60-40LE and 60-41SN transmissions is applied in 2nd and 4th gear. The B1 apply control plunger valve helps to correctly position the apply control valve to allow oil to feed the B1 brake clutch. If there is excess wear at the plunger valve sleeve, B1 brake oil is reduced, causing bind-ups and resulting in burnt B1 clutches. Installing Sonnax B1 modulator plunger valve kit 19741-03K restores hydraulic integrity to this circuit for renewed shift timing and control.
Contact a Sonnax Parts Distributor.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.