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10 

JAT-720 Dual Action Sander 

 

Troubleshooting JAT-720 High-Speed Sander

 

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 

Possible cause 

Remedy 

Tool will not start. 

Air valve closed or obstructed. 

Open valve; clear any obstructions. 

Dirt or gum deposits on 
components. 

Flush tool with gum solvent. 
If problem persists, disassemble, 
clean and lubricate internal parts. 

Rotor vanes or other components 
are worn. 

Replace worn components. 
(Replace vanes as an entire set.) 

Trigger inoperable. 

Clean trigger mechanism to ensure 
free movement. Replace 
mechanism if needed. 

Bearing(s) worn. 

Disassemble and inspect bearing. 
Grease or replace as needed. 

Starts immediately when 
air is connected without 
throttle lever being 
pressed. 

Throttle lever malfunction. 

Clean throttle lever mechanism to 
ensure free movement. Replace 
mechanism if needed. 

Excessive or abnormal 
vibration. 

Bearings worn. 

Disassemble and inspect bearing. 
Grease or replace as needed. 

Loss of power; erratic 
action. 

Low air pressure. 

Verify compressor has proper CFM 
rating for tool. 
Check compressor regulator 
setting; set air pressure to 90 psi.   
Set regulator dial on tool to 
maximum setting. 
Check for loose connections.  

Moisture or obstruction in air 
hose. 

Air supply must be clean and dry. 
Clean out air hose(s) and remove 
any kinks or bends. 

Improper size of air transmission 
lines, hoses, fittings, or 
couplings. 

Use appropriate-sized air 
lines/hoses. 
Verify proper fittings/couplings. 

Dirt or gum deposits on 
components. 

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. 

Rotor vanes are worn. 

Replace vanes (entire set). 

Excessive heat develops 
in tool. 

Insufficient lubrication. 

Lubricate with air tool oil. 

Worn components. 

Replace components as needed. 

Severe air leakage. 
(Note: Minimal escape of 
air is often normal for air 
tools.) 

Air valve obstructed or damaged. 

Clean or replace. 

Housing loose or damaged. 

Tighten or replace as needed. 

Summary of Contents for 505720

Page 1: ...Pneumatic Dual Action Sander 505720 JAT 720 Operation Parts Manual M 505720 Edition 1 02 2015 JET 427 New Sanford Road LaVergne TN 37086 Ph 800 274 6848 www jettools com Copyright 2015 JET...

Page 2: ...eeded JET has Authorized Service Centers located throughout the United States For the name of an Authorized Service Center in your area call 1 800 274 6846 or use the Service Center Locator on the JET...

Page 3: ...romium from chemically treated lumber Your risk of exposure varies depending on how often you do this type of work To reduce your exposure to these chemicals work in a well ventilated area and work wi...

Page 4: ...sensitive areas of the body and may propel small particles caught in the air stream Exercise proper caution 30 Use only recommended accessories improper accessories may be hazardous 31 Maintain tools...

Page 5: ...in this document The instructions and warnings in this manual may not encompass all possible workplace environments The operator is expected to take appropriate precautions and exercise common sense...

Page 6: ...yle Overall Length 8 3 4 in 222 25 mm Housing material Aluminum Net weight 3 99 lb 1 81 kg Shipping weight 4 41 lb 2 0 kg 1 The specified values are emission levels and are not necessarily to be seen...

Page 7: ...connection to fail Instead add a leader hose and install any quick change couplings farther down the line 6 Turn spindle lock to create either random orbit or simple rotary motion 7 Press and hold th...

Page 8: ...he air wrench is too small or the air compressor CFM is not powerful enough for the job Continued use in either capacity will cause damage to the tool Tool Pressure JET Air Tools operate on 70 to 100...

Page 9: ...JET 9 Figure 2 Recommended arrangement of air piping and air line system...

Page 10: ...abnormal vibration Bearings worn Disassemble and inspect bearing Grease or replace as needed Loss of power erratic action Low air pressure Verify compressor has proper CFM rating for tool Check compre...

Page 11: ...lowing pages To order parts or reach our service department call 1 800 274 6848 Monday through Friday 8 00 a m to 5 00 p m CST Please have the stock number and serial number of your tool available whe...

Page 12: ...12 JAT 720 Dual Action Sander 505720 JAT 720 Dual Action Sander exploded view...

Page 13: ...21 JAT720 21 Bearing 2 22 JAT720 22 Rear end plate 1 23 JAT720 23 Cylinder 1 24 JAT720 24 O Ring 7 5x2 1 Index Part No Description Qty 25 JAT720 25 Ball 1 26 JAT720 26 Rotor 1 27 JAT720 27 Rotor vane...

Page 14: ...14 JAT 720 Dual Action Sander This page intentionally left blank...

Page 15: ...JET 15 This page intentionally left blank...

Page 16: ...16 JAT 720 Dual Action Sander 427 New Sanford Road LaVergne Tennessee 37086 Phone 800 274 6848 www jettools com...

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