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SECTION Vl - TROUBLE SHOOTING
Trouble
Probable Cause
Remedy
6-1. Hoist does not operate.
1. Insufficient air pressure at
1. Check air pressure and adjust
source.
2. Brake improperly adjusted.
2. Adjust brake.
3. Clogged air intake screen.
3. Shut off air - disconnect air hose - clean
inlet swivel screen.
4. Excessive overload.
4. Reduce load.
5. Clogged valve.
5. Remove valve caps - remove any obstruc
tions, clean and lubricate valve.
6. Valve shifter not functioning.
6. Check for proper installation of drive pin in
valve shifter and control lever and also that
shifter pin is assembled solidly to throttle
valve.
7. Motor failure.
7. Disassemble motor and check rotor blades.
Replace defective parts.
6-2. Hoist will not hold load in
1. Brake out of adjustment
1. Adjust Brake.
suspension.
2. Brake lining oily, glazed or
2. Remove brake arms and replace with new.
badly worn.
3. Excessive overload.
3. Reduce load
6-3. Control lever does not return
1. Control shaft bent.
1. Remove shaft and straighten or replace.
to horizontal position.
2. Foreign material, rust or
2. Remove shaft and clean. Lubricate bearings
corrosion causing it to bind
brake cam and valve shifter.
3. Foreign material, rust or
3. Clean control cylinders.
corrosion in control cylinders
or pendant throttle control.
4. Brake improperly adjusted.
4. Adjust brake
6-4. Hoist loses power.
1. Insufficient air pressure.
1. Check air pressure and adjust.
2. Clogged air intake screen.
2. See this Section, paragraph 1.
3. Clogged muffler screen.
3. Remove throttle valve housing. Clean
screen and muffler.
4. Worn or broken rotor blades.
4. Replace rotor blades.
6-5. Cannot regulate speed by
1. Brake improperly adjusted.
1. Adjust brake.
control handles.
2. Speed adjustment screws
2. Readjust screws.
improperly set.
6-6. Cannot regulate speed by
1. Brake improperly adjusted.
1. Adjust brake.
pendant handle.
2. Control cylinders improperly
2. Adjust control cylinder set screws.
adjusted.
6-7. Hoist lifting or lowering speed
1. Valve shifter or control shaft
1. Repair or install new parts, and lubricate.
differs from rated speed at full load.
bent or damaged.
2. Incorrect air pressure or
2. Check pressure near hoist when hoist is
inadequate air supply.
operating.
3. Speed adjustment screws
3. Readjust screws. See Figure 2-4.
improperly set.
4. Loss of power.
4. See paragraph 6-4.
