Troubleshooting Guide - MIRKA MROS125 Notice D'utilisation

Symptom
Low Power and/or Low Free
Speed
Air leakage through the Speed
Control and/or Valve Stem.
Vibration/Rough Operation
Note: (All Sections referred to under "Solution" are located at the end of the manual in "Service Instructions")

Troubleshooting Guide

Possible Cause
Insufficient Air Pressure
Clogged Muffler(s)
Plugged Inlet Screen
One or more Worn or Broken Vanes
Internal air leakage in the Motor Housing
indicated by higher than normal air con-
sumption and lower than normal speed.
Motor Parts Worn
Worn or broken Spindle Bearings
Dirty, broken or bent Valve Spring, Valve
or Valve Seat.
Incorrect Pad
Addition of interface pad or other material
Improper lubrication or buildup of foreign
debris.
Worn or broken Rear or Front Motor
Bearing(s)
Check air line pressure at the Inlet of the Sander
while the tool is running at free speed. It must be 6.2
Bar (90 psig/620 kPa).
See the "Housing Disassembly" section for Muffler
removal. The Item 20 Muffler can be back flushed
with a clean, suitable cleaning solution until all
contaminates and obstructions have been removed. If
the Muffler can not be properly cleaned then replace
it. Replace Item 21, Muffler Insert (See the "Housing
Assembly" Section).
Clean the Inlet Screen with a clean, suitable cleaning
solution. If Screen does not come clean replace it.
Install a complete set of new Vanes (all vanes must
be replaced for proper operation). Coat all vanes with
quality pneumatic tool oil. See "Motor Disassembly"
and "Motor Assembly".
Check for proper Motor alignment and Lock Ring
engagement. Check for damaged O-Ring in Lock
Ring groove. Remove Motor Assembly and Re-Install
the Motor Assembly. See "Motor Disassembly" and
"Motor Assembly".
Overhaul Motor. Contact authorized Mirka Service
Center.
Replace the worn or broken Bearings. See "Mini Ran-
dom Orbital Head Disassembly" and "Mini Random
Orbital Head Assembly".
Disassemble, inspect and replace wore or damaged
parts. See Steps 2 and 3 in "Housing Disassembly"
and Steps 2 and 3 in "Housing Assembly".
Only use Pad Sizes and Weights designed for the
machine.
Only use abrasive and/or interface designed for the
machine. Do not attach anything to the Sanders Pad
face that was not specifically designed to be used
with the Pad and Sander.
Disassemble the Sander and clean in a suitable
cleaning solution. Assemble the Sander. (See "Ser-
vice Manual")
Replace the worn or broken Bearings. See "Motor
Disassembly" and "Motor Assembly".
7
Solution