TM 10-3930-669-34 15-7.  MAST PRIMARY CYLINDER REPAIR. This task covers: a. Disassembly b. Cleaning/Inspection c. Assembly INITIAL SETUP Tools and Special Tools Materials/Parts - Continued Tool Kit, General Mechanic’s: Automotive Ring, Wear (Item 1, Appendix E) Packing, Preformed Vise, Pipe, Chain (Item 5, Appendix E) Wire, Lock Pan, Drain (Item 11, Appendix E) Wiper Seal Materials /Parts Seal Oil, Hydraulic (Item 15, Appendix B) Screw, Removal (2) Solvent, Dry-cleaning (Item 20, Appendix B) Cartridge, Flow Equipment Condition Ring, Backup Mast primary cylinder removed Ring, Wear (2) (Para 13-2) a. Disassembly. CAUTION Do  not  allow   threaded   or   machined surfaces    to    come    in    contact    with other    metal    surfaces.        Clearances between  cylinder  components  are  is very  small,  any  minor  damage  done during     disassembly     could     require component replacement or make assembly difficult. (1) Position mast primary cylinder (1) in chain vise. 15-45