Seat Belt Systems: Testing and Inspection

If the seat belt retractor of a new seat belt assembly has been bolted into a damaged or distorted mounting area, the new seat belt retractor could be warped and may not function. If this is the case, reshape the sheet metal back to its original shape and structural integrity and install another new complete seat belt assembly. Perform a function test of the new seat belt assembly as follows:

1. The driver will buckle up and proceed to a safe teat area. A passenger should be buckled into the seat where the belt is to be tested.

NOTE: Do not fully extend the rear shoulder safety belt in order to preclude the possibility of a false feeling (full extension vs. lockup).

2. After reaching a safe area to perform sudden stops, the driver will attain a speed of approximately 8 kph (5 mph). The driver should inform the passenger that he is preparing to make a severe brake application. At this time, both driver and passenger should grasp their respective shoulder harness and prepare to lean slightly forward at the moment the brake application is made.

3. The driver will make a maximum brake application (approximately 9.75m/sec/sec [32 ft/sec/sec]) without tire skid. (The maximum brake application should be on dry concrete or equivalent hard road surface, never on a wet or gravel road.) The driver and passenger should lean forward slightly into the shoulder harness. At this instant, the safety belts should look up without belt webbing payout.

WARNING: THE DRIVER AND PASSENGER MUST BE PREPARED TO BRACE THEMSELVES IN THE EVENT THE RETRACTOR DOES NOT LOCK.

4. If there is a lockup of both shoulder straps, the safety belt assemblies are functioning properly. Should either or both retractors fail to lock up at the 8 kph (5 mph) speed, the test should be repeated at a constant 24 kph (15 mph).

5. If either or both shoulder safety belts do not lock up at the 24 kph (15 mph) teal, service malfunctioning safety belts. Remove the retractor and rework the sheet metal back to its original shape and structural integrity in the retractor's mounting surface. Install the retractor assembly and test the safety belt assembly(ies).