TM 10-3930-659-34 4-73.  AIR COMPRESSOR ASSEMBLY REPAIR (Con’t). 5. Remove relief valve (16) from cylinder head (3). 6. Remove coupling (12), elbow (13), nipple (14), and elbow (15) from cylinder head (2). NOTE Both cylinder heads are removed and disassembled the same way.  One cylinder head is illustrated. 7. Remove two screws (20), washers (19), cylinder (17), and piston rider ring (18) from motor (4). 8. Mark  cylinder  head  (3)  and  cylinder  (17)  to  aid during assembly. 4-301