Apeks T20 1st Stage Service Manual. contents include Introduction Safety Precautions General Procedures Maintenance Schedules Initial Inspection and Pre-Test Infrequently Used Regulators Work Area & Required Tools O-ring Removal Lubrication Recommended Tools Lubricant and Cleaner Disassembly Procedures Disassembly of Yoke Connector Disassembly of DIN Connector Cleaning & Inspection Reassembly Procedures Reassembly of Yoke Connector Reassembly of DIN Connector Final Adjustment and Testing Procedures Troubleshooting Repair and Replacement Parts Schematic Drawing