Trouble
Low power or low free speed
Rough operation
Scoring
Air leaks
SAVE THESE INSTRUCTIONS. DO NOT DESTROY.
MAINTENANCE SECTION
TROUBLESHOOTING GUIDE
Probable Cause
Insufficient air pressure at the
inlet
Plugged Screens
Worn or broken Vanes
Worn or broken Cylinder
Improper lubrication or dirt
build–up in the motor
Worn or broken Rear Rotor
Bearing or Front Rotor Bearing
Worn Rotor Key
Bent Arbor
Improper assembly
Rotor Bearing Seal misalignment Loosen the Cylinder Case Screws. Rotate the
Worn Valve Seat or Valve Seat
Washer
Worn Throttle Valve Seals
Worn Cylinder Case Gasket
between the Cylinder Case and
the Guard
Distorted face on the Cylinder
21
Solution
Check air line pressure at the Inlet of the Tool.
It must be 90 psig (6.2 bar/620 kPa).
Clean the Inlet Bushing Screen in a clean, suitable,
cleaning solution. If it cannot be cleaned,
replace it.
Never operate a Grinder without an Inlet Screen.
Ingestion of dirt into the Grinder can, in some
cases, cause an unsafe condition.
Install a complete set of new Vanes.
Replace the Cylinder if it appears cracked or if the
bore is wavy or scored.
Lubricate the Grinder as instructed in LUBRICA-
TION SPECIFICATION. If lubrication does not
result in satisfactory operation, disassemble the
motor, and inspect and clean all parts.
Examine each Bearing. Replace the Rear Rotor
Bearing Seal Assembly if worn or damaged or re-
place the Front Rotor Bearing.
Replace the Key. Check the Arbor and Rotor for
key slot wear and replace if necessary.
Mount the Arbor on centers. Check bearing diame-
ter runout with an indicator. Replace the Arbor if
runout exceeds 0.002" (0.051 mm) Total Indicator
Reading.
Make certain that all motor parts are properly
aligned prior to clamping the motor assembly.
spindle by hand to align the seal. Tighten the
screws to 14 ft–lb (19 Nm) torque. Spindle must
rotate freely.
Replace worn parts.
Replace both Seals.
Replace the Gasket.
Polish lightly using fine emery cloth on a flat
metal plate to remove high spots. If the tool has
been dropped and the Cylinder Case is damaged,
replace it with a new Cylinder Case Assembly.