Jet JAT-400 Operations & Parts Manual page 10

Troubleshooting JAT-400 Micro Die Grinder
Any disassembly of the tool should be done by qualified service personnel. For problems not addressed
below, contact JET technical service at 800-274-6846.
Problem
Tool will not start.
Starts immediately as soon
as air is connected while
air regulator is off.
Excessive or abnormal
vibration.
Loss of power; erratic
action.
Severe air leakage.
(Note: Minimal escape of
air is often normal for air
tools.)
Excessive heat develops
in tool.
10 JAT-400 Micro Die Grinder
Possible cause
Air valve closed or obstructed.
Dirt or gum deposits on
components.
Rotor vanes or other components
are worn.
Air regulator malfunction.
Bearing(s) worn.
Air regulator malfunction.
Improper lubrication.
Bearings worn.
Low air pressure.
Moisture or obstruction in air
hose.
Improper size of air transmission
lines, hoses, fittings, or
couplings.
Dirt or gum deposits on
components.
Rotor vanes are worn.
Air valve obstructed or damaged.
Housing loose or damaged.
Improper lubrication.
Remedy
Open valve; clear any obstructions.
Flush tool with gum solvent.
If problem persists, disassemble,
clean and lubricate internal parts.
Replace worn components.
(Replace vanes as an entire set.)
Inspect and repair air regulator.
Disassemble and inspect bearing.
Grease or replace as needed.
Inspect and repair air regulator.
Lubricate properly according to
instructions in this manual.
Disassemble and inspect bearing.
Grease or replace as needed.
Verify compressor has proper CFM
rating for tool.
Check compressor regulator
setting; set air pressure to 90 psi.
Check for loose connections at air
inlet, o-rings, etc.
Air supply must be clean and dry.
Clean out air hose(s) and remove
any kinks or bends.
Use appropriate-sized air
lines/hoses.
Verify proper fittings/couplings.
Flush tool with gum solvent.
Check and clean air filter on
compressor.
Clean external areas of tool. If
problem persists, disassemble,
clean and lubricate internal parts.
Replace vanes (entire set).
Clean or replace.
Tighten or replace as needed.
Lubricate properly according to
instructions in this manual.