Cause:
The pump flow control canister and plunger valve wear, allowing the plunger valve to stick open and/or leakage to occur. The canister O-ring relaxes and pressure bleeds past it.
Correction:
Sonnax pump flow control valve kit includes a harder canister with more support for the plunger valve, which prevents sticking. The assembly also includes a case-hardened plunger valve with self-centering annular groves, a replacement spring, and larger O-ring for improved sealing.
In Ford 5R55N, 5R55S and 5R55W units, the OE flow control valve is designed to increase pump efficiency by rerouting excess line pressure back to the suction side of the pump. It is common for the plunger valve to become stuck open, or for the canister to wear. This decreases line pressures and results in delayed engagements. The Sonnax pump flow control valve kit eliminates the sticking and wear problems with redesigned and precision-machined parts.
Harder canister material resists wear and has improved valve support to prevent sticking
Plunger valve is made from case-hardened steel and has annular grooves to prevent side loading
Larger O-ring eliminates pressure loss at the pump face
Canister restores the regulated line orifice to improve valve and hydraulic stability
Drop-in replacement
Symptoms:
Cause: The pump flow control canister and plunger valve wear, allowing the plunger valve to stick open and/or leakage to occur. The canister O-ring relaxes and pressure bleeds past it.
Correction: Sonnax pump flow control valve kit includes a harder canister with more support for the plunger valve, which prevents sticking. The assembly also includes a case-hardened plunger valve with self-centering annular groves, a replacement spring, and larger O-ring for improved sealing.
In Ford 5R55N, 5R55S and 5R55W units, the OE flow control valve is designed to increase pump efficiency by rerouting excess line pressure back to the suction side of the pump. It is common for the plunger valve to become stuck open, or for the canister to wear. This decreases line pressures and results in delayed engagements. The Sonnax pump flow control valve kit eliminates the sticking and wear problems with redesigned and precision-machined parts.
Contents:
SONNAX Installation Instructions