Section 01-20A: Restraints, Active
1996 F-150, F-250, F-350, F-Super Duty and Bronco Workshop Manual
SERVICE PROCEDURES

Safety Belt Lockup Functional Test Procedure

 

  1. Driver will buckle up and proceed to a safe test area. If RH front or rear passenger safety belt must be tested, a passenger should be buckled into RH front or rear seat. (The RH front belt may be tested using a driver only, providing driver has the ability to grasp RH front shoulder belt and extend it approximately 66 cm (26 inches) with no compromise to safe driving). This method applies to 8 km/h (5 mph) test only.

  1. After reaching a safe area to perform sudden stops, driver will attain a speed of approximately 8 km/h (5 mph). The driver should advise the passenger (if applicable) to prepare for a severe brake application. At this time, both driver and passenger should grasp their respective shoulder safety belts and prepare to lean slightly forward at the moment brake application is made.

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

    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.)

  1. The driver and passenger should lean forward slightly into shoulder safety belt. At this instant, belts should lock up without any noticeable webbing payout.

  1. If there is a lockup of both shoulder belts, safety belt assemblies are functioning properly.

  1. 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.

    Should either or both 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 driver and passenger if both front retractors are to be tested.)

  1. If either or both shoulder safety belts do not lock up at 24 km/h (15 mph) test, return vehicle for service of malfunctioning safety belts. Remove retractor and rework sheet metal in retractor's mounting area, if necessary. Install retractor assembly and retest safety belt assembly(s) as previously stated.