Loss of pressure control to the secondary pulley. Low pressure to the pulley causes chatter, push belt slip, surface fretting and metal contamination. With low pressure, pully diameter will not change and ratio remains the same.
Refurbish the bore using the Sonnax tool kit and install the Sonnax valve and end plug.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
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.