f) Inspect electric brake friction linings and friction surfaces for wear, scoring or warpage. Check air gap  between  armature  and  field.    If  the  gap exceeds   0.045   inch,   adjust   as   described   on page 16. g) Inspect    the    liftwheel    pockets    for    wear    as evidenced  by  a  widening  and  deepening  of  the load  end  of  pocket.    That  condition  will  cause the chain to lift up in pocket and result in binding between  liftwheel  and  chain  guides.    Severely worn liftwheel should be replaced. h) Inspect   the   chain   guides   for   wear   or   burring where chain enters hoist.  Severely worn guides should be replaced. i) Inspect  load  chain,  chain  guides  and  liftwheel pockets  for  clogging  with  foreign  matter  which causes  chain  to  bind.    See  hoist  lubrication  of chain guides, liftwheel, lower sheave wheel and load chain on page 16. j) Inspect trolley trackwheels for external wear on the  tread  and  flange,  and  for  wear  on  internal bearing  surfaces  as  evidenced  by  a  looseness on the stud. k) Inspect  collector  wheels  or  collector  shoes  and cotter  pins  for  wear.    Check  the  wheels  and studs for corrosion and free turning.  Badly worn parts should be replaced. l) Inspect  the  gasket  between  the  gear  housing and back frame for signs of leaks.  Tighten the screws holding back frame to gear housing.  If a leaking  condition  persists  repack  housing  and gears with grease and install a new gasket. Any   deficiencies   noted   are   to   be   corrected before the hoist is returned to service.  Also, the external   conditions   may   show   the   need   for disassembly to permit a more detailed inspection which, in turn, may require the use of nondestructive type testing. TESTING: Prior to initial use, all altered or repaired hoists or   used   hoists   that   have   not   been   operated   for   the previous   12   months   shall   be   tested   by   the   user   for proper  operation.    Test  the  unit  first  in  the  unloaded state and then with a light load of 50 pounds times the number load supporting parts of load chain to be sure it operates properly and the brake holds the load when the control is released; then test with a * load of 125%/e of rated capacity. In addition, hoists in which load sustaining parts have  been  replaced  shall  be  tested  with  *  125C%,  of rated capacity by or under the direction of an appointed person    and    a    written    report    prepared    for    record purposes. After this test, the function of the Protector is to be   tested.      If   the   Protector   permits   lifting   a   load   in excess of 180%c of rated load it should be replaced. * If the Protector prevents lifting of a load of 125%c of rated capacity, reduce load to rated capacity. NOTE  :  For  additional  information  on  inspection  and testing,    refer    to    Code    B30.16    "Overhead    Hoists", obtainable  from  American  National  Standards  Institute, 1430 Broadway, New York, N.  Y. 10018 U.S.A. HOOKS: Hooks  damaged  from  chemicals,  deformations or cracks, or that have more than a 10 degree twist from the  plane  of  the  unbent  hook  or  excessive  opening  or seat wear must be replaced. Also,   on   latch   type   hooks,   hooks   that   are opened and allows the latch to disengage the tip, must be replaced. Any hook that is twisted or has excessive throat opening indicates abuse or overloading of the unit. Other  load  sustaining  components  of  the  hoist should be inspected for damage. Check to assure latch is not damaged or bent. The  charts  below  should  be  used  to  determine when the hook must be replaced.  On latch type hooks, remove  latch  to  measure  opening.    Be  sure  to  replace latch after measurements are completed. FIGURE 11. 13