Brake Caliper May Detach

Affected vehicles (2)

Component / system

Defect

Navistar, Inc. (Navistar) is recalling certain 2024-2025 IC Bus EVSB and 2024-2025 CESB school buses. The brake caliper mounting bolts may not have been properly tightened, allowing the brake caliper to detach from the anchor plate.

Risk / consequence

A detached brake caliper can cause a loss of braking ability, increasing the risk of a crash.

Remedy

Navistar will inspect, tighten, and replace any missing bolts as necessary, free of charge. Owner notification letters were mailed November 4, 2024. Owners may contact Navistar Customer Service at 800-448-7825. Navistar's number for this recall is 24513.

Chronology of events

1. Mar 27, 2024

   3/27/2024: Navistar receives a field service report on a bus where 4 out of 6 air disc brake caliper mounting bolts are missing (remaining 2 were loose) on the left rear wheel end. It was also noted that the 2 remaining bolts did not appear to have inspection marks to indicate that the bolts were properly torqued. At this time, there were no additional reports of missing or loose caliper mounting bolts.

2. Jul 8, 2024

   7/8/2024: Navistar Product Safety begins an investigation into the issue reported in the field report after a warranty search found 4 Prior to Delivery (PTD) and 3 In-service warranty claims for loose or missing caliper bolts. Summary to be found in Appendix document uploaded to NHTSA portal.

3. Aug 28, 2024

   8/28/2024: The field service report was a topic of discussion during the quarterly Safety Evaluation List meeting between Navistar and the NHTSA. At the meeting Navistar indicated that it was aware of the 7 warranty claims of loose or missing bolts on an air disc brake caliper, but that no specific trend in failure mileage or failure location was identified at that time.

4. Aug 29, 2024

   8/29/2024: Navistar Product Safety became aware of 2 additional reports of loose and missing bolts. Summary to be found in Appendix document uploaded to NHTSA portal.

5. Sep 3, 2024

   9/3/2024: The Tulsa Bus Plant began an in -station 100% inspection and manual recording of caliper mounting bolt torque data on all air disc brake buses establishing the clean point.

6. Sep 3, 2024

   9/3/2024 thru 9/16/2024: The Tulsa Bus plant performed a yard inspection of 385 buses finding all were torqued correctly.

7. Sep 3, 2024

   9/3/2024 thru 9/23/2024: Navistar Product Safety and R&D work to determine the potential vehicle level effects of loose and/or missing caliper mounting bolts and the effect of mileage on the occurrence of the issue.

8. Sep 16, 2024

   9/16/2024: The Tulsa Bus Plant upgrades DC torque tool traceability to electronically replace the manual inspection. Torque data then reviewed daily to ensure all bolts on every bus were torqued properly. Improvements include fea

Notification schedule

Dealer notification

NOV 15, 2024 - NOV 15, 2024

Owner notification

NOV 22, 2024 - NOV 22, 2024

Documents