Tire Maintenance Guide: Safety Tips & Common Defects

1. Tire Safety

2. Running to Destruction • Its not a safe practice • Potential for loss of control • Potential for debris to injure personnel if tire ruptures • Tires with damaged structural component create safety hazard

3. Structural Components • Tire manufacturer consulted since tires have different designs • Inspection of defects, such as determining depth of cuts, on pressurized tire can create safety hazard - deflate tire before inspection

4. Belts • Impact /penetration belts between tread & structural belts • Exposed impact /penetration belts inspected • Exposed structural belts removed from service • Ply rating is nominal strength rating & doesn’t indicate number of belts • Continental Tire considers tire with any belt exposed not “viable”

5. Sidewall • 1 structural belt in sidewall with a non-structural turn up of belt in bead area • Exposed turn up wires inspected • Exposed sidewall structural belt wires removed from service

6. Radial Tire Tread Shoulder Belts Sidewall Ply Turn Up Chafer Bead Bundle Air Chamber

7. Rims • Damaged rims can damage tires • Rims with minor damage scheduled for maintenance, cracked rims or damaged lock rings immediately removed from service • Wheel driver keys not considered structural components • Missing keys allow rim to slip, wear o-ring, & cause air loss - schedule for maintenance

8. Damaged Rim Driver Key Insert

9. Structural Components • Many defects in tread & sidewall areas can be repaired • Manufacturer establishes tire’s repair limits • Proper repair is essential to maintain tire safety • Moving tire with structural defect to inside rear axle position is unsafe

10. Maintenance Training • Develop schedules & out-of-service criteria • Equipment operators visually inspect tires during pre-shift inspection & trained to recognize hazardous tire defects • Maintenance personnel trained to safely & properly inspect & repair

11. Maintenance Training • Society of Automotive Engineers: Off Road Tire Conditions Removal Guidelines- Draft • Draft available for review, comments requested • Note - this document does not affect Agency policy

12. Defects • Bulge: area of separation packed with rubber that has migrated from adjoining area of separation. • Blister: localized bubble on tire surface • Chipping: flaking or tearing away small bits of tread rubber

13. Defects • Chunking: tearing or breaking away pieces of tread rubber • Cracks: splits or narrow breaks in rubber compounds not caused by foreign object • Cut: damage made by sharp or jagged objects

14. Typical defects • Exposed cord: belt, ply or steel chafer/bead area reinforcement seen • Puncture: air chamber penetrated by foreign object causing air loss • Separation: parting of de-bonding of any adjacent parts

15. 10 Do’s • Pick correct tire for the job • Check air pressure • Conduct pre-shift inspections • Get monthly or bimonthly professional inspections • Repair problems early

16. 10 Do’s • Rotate tires • Establish tracking program • Conduct out-of-service surveys • Limit weight & loads • Care about the tires

17. 10 Don'ts • Just put on cheapest tire • Let air down for smooth ride • Just kick tires & go • Assume you know everything • Just let things go • Let front tires be your worst tires

18. 10 Don’ts • Assume you are doing good with your tire program • Throw away tires without knowing why • Run overloaded when you could have tires that can carry the load more effectively • Tell operators to not worry about the tires, just run them

19. Safety References • Manufacturers, tire industry organizations, & machine manufacture’s tire safety & maintenance information