JLG 1200SJP Service Maintenance Manual page 130

SECTION 3 - CHASSIS & TURNTABLE
6. Thoroughly wash end cover (2) in proper solvent and
blow dry. Be sure the end cover valve apertures, includ-
ing the internal orifice plug, are free of contamination.
Inspect end cover for cracks and the bolt head recesses
for good bolt head sealing surfaces. Replace end cover
as necessary.
NOTE:
A polished pattern (not scratches) on the cover from rota-
tion of the commutator (5) is normal. Discoloration would
indicate excess fluid temperature, thermal shock, or excess
speed and require system investigation for cause and close
inspection of end cover, commutator, manifold, and rotor
set.
7. Remove commutator ring (6). Inspect commutator ring
for cracks, or burrs.
3-84
8. Remove commutator (5) and seal ring (3) Remove seal
ring from commutator, using an air hose to blow air into
ring groove until seal ring is lifted out and discard seal
ring. Inspect commutator for cracks or burrs, wear, scor-
ing, spalling or brinelling. If any of these conditions exist,
replace commutator and commutator ring as a matched
set.
9. Remove manifold (7) and inspect for cracks surface scor-
ing, brinelling or spalling. Replace manifold if any of
these conditions exist. A polished pattern on the ground
surface from commutator or rotor rotation is normal.
Remove and discard the seal rings (4) that are on both
sides of the manifold.
– JLG Lift – 3121142