1963 - 1967 Corvette: Engineering Service Letter: Steering Effort on Booster Type Power Steering Vehicles
Subject: Steering Effort on Booster Type Power Steering Vehicles
Model and Year: 1963 - 1964 Chevrolet, 1963 - 1967 Corvette, 1963 - 1967 Chevy II
Source: Chevrolet Engineering Service Letter - UPC IX - Steering
Page Number: NA
Date: January - February 1967
Lack of power assist on vehicles using the booster cylinder may be caused by too much lubricant being injected into the valve and adapter. This could limit travel of the ball stud which actuates the valve controlling the flow of hydraulic fluid to the power cylinder resulting in increased steering effort.
To correct the above condition, remove the lubrication fitting and actuate the steering linkage without the engine running. This will pump out the excess lubricant and restore the system to its original condition. Re-install fitting. The bleeder passages under the adapter stud seal clamp should also be cleaned to remove any coagulated grease which could prohibit effective bleeding.