Brake Drum and Hub Radial Runout Check - On-Vehicle

BRAKE DRUM AND HUB RADIAL RUNOUT CHECK (ON-VEHICLE)

1. Remove road wheel.
2. Remove brake drum and install on hub backwards; secure drum with two wheel nuts also installed backwards (flat side toward drum).





3. Fasten a dial indicator to the knuckle or strut-to-knuckle fastener.
4. Position dial indicator tip against brake drum shoe surface.
5. Rotate the drum to the lowest reading.
6. Zero the dial indicator.
7. Rotate the drum one complete revolution and observe Total Indicated Runout (TIR).
7.1 If combined brake drum and hub radial runout does not exceed 0.28 mm (0.011 inch), proceed to step 8.
7.2 If combined drum and hub radial runout exceeds 0.28 mm (0.011 inch), proceed to step 14.
Maximum TIR (combined brake drum and hub): 0.28 mm (0.011 inch)
8. Move dial indicator neck to allow removal of the brake drum. It is not necessary to remove dial indicator from the knuckle or strut-to-knuckle fastener.
9. Remove brake drum from hub and turn 180 degrees and again, install on hub backward. Secure brake drum with two wheel nuts also installed backwards (flat side toward brake drum).
10. Position dial indicator tip against brake drum shoe surface.
11. Rotate the brake drum to the lowest reading.
12. Zero the dial indicator.
13. Rotate the brake drum one complete revolution and observe TIR.
Maximum TIR (combined brake drum and hub): 0.28 mm (0.011 inch)
13.1 If combined brake drum and hub radial runout does not exceed 0.28 mm (0.011 inch), brake drum and hub are within specification and no repair is required.
13.2 If combined brake drum and hub radial runout exceeds 0.28 mm (0.011 inch), proceed to step 14.
14. Remove brake drum and install on a brake lathe.
15. Fasten a dial indicator to the lathe.
16. Position dial indicator tip against brake drum shoe surface.
17. Rotate brake drum to lowest reading.
18. Zero the dial indicator.
19. Rotate the brake drum one complete revolution and observe total indicated runout.
Maximum TIR (brake drum): 0.15 mm (0.006 inch)
If brake drum radial runout exceeds 0.15 mm (0.006 inch), refinish brake drum as long as refinishing does not exceed brake drum maximum diameter of 200.6 mm (7.90 inch) after turning. If brake drum exceeds maximum diameter, replace the brake drum.





20. Subtract TIR measurement obtained in step 19 (brake drum runout) from TIR measurement obtained in step 7 (combined brake drum and hub runout). The difference between these two readings represents hub runout.
Maximum TIR (combined brake drum and hub): 0.28 mm (0.011 inch)
If hub runout exceeds 0.13 mm (0.005 inch), replace the hub and bearing assembly.