In listed VW/Audi units, the boost regulator valve, which regulates EPC pressure feed to the main regulator valve, is secured in the valve body with a ratcheting end plug. Attempting to turn the end plug in order to tune line pressure will cause the end plug to break. Additionally, the boost regulator valve can cause significant wear to the bore, allowing EPC leakage, which can result in low line pressure, soft shifts and burned clutches. This bore should be inspected for wear on every rebuild.
The worn bore may be salvaged using the Sonnax oversized boost regulator valve 119940-05K for 01M, 01N, 01P units, or 119940-07K for 096, 097 and 098 units. Sonnax offers ratcheting end plug 119940-22 and adjustment tool 119940-22 to allow line pressure to be fine-tuned.