TM 10-3930-664-24 13. Measure   valve   springs.      Free   length   shall   be approximately 2.190 in.  (55.63 mm). 14. Check  valve  spring  tension  using  spring  tester. A    minimum    load    of    65    lbs    is    required    to compress  spring  to  a  height  of  1.94  in.    (49.25 mm). D.  REPAIR 1. Repair of the cylinder head assembly is limited to grinding   and   lapping   detailed   in   INSPECTION procedures. 2. All other repair consists of removal and replacement of defective, deformed, or damaged components. E.  ASSEMBLY 1. Install   new   valve   stem   seals   (7)   onto   valve guides. 2. Lubricate valve stems with lubricating oil.  Install valves (1, 2) into proper bores. 3. Install assembled valve springs (3) and retainers (6) into cylinder head (5). 4. Compress  valve  springs  (3)   and   install   collets (4).  Release valve springs. WARNING Wear  eye  protection  when  checking collets.      If   collets   are   not   properly installed, they can fly out when stems are hit with hammer. 5. Hit   valve   stems   with   soft   headed   hammer   to ensure collets are seated. FOLLOW-ON MAINTENANCE: Install cylinder head assembly (para.  3-8) END OF TASK 4-13