Seat Belt Systems: Testing and Inspection

Continuous Loop Shoulder/Lap Belt Test

1. Driver will buckle up and proceed to a safe test area. If passenger safety belt must be tested, a passenger should be buckled into seat. (The passenger belt may be tested by the driver, providing that the driver has the ability to grasp the passenger belt and extend it approximately 660 mm (26 inches) with no compromise to safe driving. This applies to the 8 km/h (5 mph) test only).

NOTE: The shoulder belt should not be extended fully to prevent 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 km/h (5 mph). The driver should inform the passenger (if applicable) that he is preparing to make a severe brake application. At this time, both the driver and passenger should grasp their respective shoulder harnesses and prepare to lean slightly forward at the moment brake application is made.

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

3. The driver will make a maximum brake application 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, belts should lock up without webbing payout.
4. If there is a lockup of shoulder straps, safety belt assemblies are functioning properly. Should retractors fail to lock up at the 8 km/h (5 mph) speed, repeat the test at a constant 24 km/h (15 mph). This test must be performed with a passenger if passenger belt is to be tested.

NOTE: If the retractor of a new safety belt assembly has been bolted into a damaged or distorted mounting area, the new retractor could be warped and may not function. If this is the case, reshape the sheet metal and install another new complete safety belt assembly.

5. If shoulder belts do not lock up at 24 km/h (15 mph) test, return the vehicle for service of the malfunctioning seat belts. If necessary, remove retractor and rework sheet metal at retractor's mounting surface. Install retractor assembly and test safety belt assemblies as previously stated.