Minnich A-1C, Operators & Service Manual

Page: 20 / 73

- 20 -
TROUBLE SHOOTING AIR DRILL
IF SYMPTOMS OF POOR PERFORMANCE DEVELOP, THE FOLLOWING CHART CAN BE USED AS A GUIDE TO
DETERMINE THE PROBLEM. WHEN DIAGNOSING FAULTS IN OPERATION OF THE AIR DRILL, ALWAYS CHECK
THAT THE COMPRESSOR IS SUPPLYING THE CORRECT SCFM AND AIR PRESSURE AS LISTED IN THE TABLE
PROBLEM CAUSE REMEDY
DRILL NOT GETTING AIR
1. ON MULTI DRILL UNITS, SWITCH AIRLINE WITH
DRILL THAT IS WORKING PROPERLY. IF DRILL
NOW RUNS CHECK THE AIR CONTROL VALVE.
IF THE VALVE WORKS, CHECK THE DRILL.
2. CHECK VALVE ON AIR COMPRESSOR AND
DRILL UNIT TO BE CERTAIN THEY ARE
COMPLETELY OPEN.
3. CHECK COMPRESSOR. IT SHOULD HAVE
100SCFM PER DRILL AND 110PSI AT DRILL
MANIFOLD WHEN DRILLING WITH LARGE
DRILLS.
4. MAKE CERTAIN ALL FITTINGS ARE
CONNECTED PROPERLY AND NOT LEAKING.
COUPLING OR HOSE
OBSTRUCTION
REMOVE OBSTRUCTION.
FAILURE IN THE ELECTRICAL
CIRCUIT
CHECK SWITCHES, CONNECTIONS, COILS, GROUND &
VOLTAGE. IF THE POWER UNIT (BACKHOES, GRADER,
ETC.) IS BEING JUMP STARTED, CHECK THE AMPS &
VOLTAGE BEING SUPPLIED TO COILS FROM THE
BATTERY, IT MAY BE TOO LOW.
FAILURE OF DRILL SOLENOID
VALVE (MULTI DRILL UNITS WITH
REMOTE ELECTRICAL
CONTROLS)
CHECK VALVE - YOU SHOULD BE ABLE TO FEEL THE
SOLENOID MOVE WHEN IT IS ACTUATED. MAKE SURE
YOU HAVE CURRENT TO THE SOLENOID COIL.
REPLACE THE SOLENOID IF THERE IS NO MOVEMENT.
DRILL DOES NOT RUN
MECHANICAL FAILURE OF DRILL
DISASSEMBLE THE DRILL & INSPECT IT FOR
DAMAGED PARTS.