Seat Belt Systems: Testing and Inspection
WARNING: After every accident the seat belt system must be inspected systematically! If damage is determined when inspecting the check points, customer must be in formed regarding necessity of changing belts.
Check points:
- Check belt webbing.
- Check inertia reel (locking effect).
- Visually check belt lock.
- Check belt lock function.
- Check belt guides and lock tongue.
- Check securing parts and mounting points.
- Checking lap belt automatic retractor.
NOTE: If customer refuses to have a damaged seat belt replaced, appropriate note should be made.
Belt webbing, checking
- Pull belt completely out of inertia reel or lap belt adjustment tongue.
- Inspect belt webbing for dirt and, if necessary, wash with mild soap solution. Also refer to Owners Manual.
- Replace seat belt complete with belt lock if either of the following illustrated damage examples (1 and 2) are determined on accident vehicle.
1 - Belt webbing cut, torn or chafed:
2 - Webbing loops on belt edge torn:
3 - Burn marks from cigarettes or similar:
- If damage as illustrated under points 1, 2 or 3 is determined on vehicle which has not been involved in an accident, it is sufficient to replace damaged belt only.
Inertia reel locking effect
Inertia reel has two locking functions.
First locking function is initiated by belt being jerked out of reel (belt extraction acceleration).
Checking:
Pull belt out of inertia reel with firm jerk.
- No locking effect - replace seat belt complete with belt latch.
- If difficulties are experienced when pulling belt out or reeling belt in first check whether position of inertia reel has been altered.
Second locking function is initiated by change in vehicle movement sequence (vehicle-dependent locking function).
Checking:
Fasten seat belt. Accelerate vehicle to 20 km/h (13 mph) and then carry out emergency braking with foot brake.
- Replace seat belt complete with belt latch if seat belt is not locked by locking mechanism during braking procedure.
WARNING: For safety reasons, road test should performed in traffic-free area to ensure that other motorists/pedestrians etc. are not endangered.
Belt latch, visual check
Inspect belt latch for cracks and fracturing. Replace seat belt complete with belt latch it damage is determined.
Belt latch, functional check
Checking latch mechanism:
- Push locking tongue into belt latch until it engages audibly. Check whether locking mechanism is properly engaged by pulling firmly on belt. Replace seat belt complete with belt latch if belt tongue fails even only once to engage properly in belt latch during at least 5 tests.
Checking release mechanism:
- Release seat belt by pressing button on belt latch with finger pressure. When belt is slack, locking tongue must spring out of belt latch on its own.
- Carry out test at least 5 times. Seat belt complete with belt latch must be replaced if belt tongue fails to spring out of latch even only once.
WARNING: Under no circumstances whatsoever may lubricant be used to eliminate noise or stiffness at belt latch buttons.
Checking belt guides and locking tongues
Plastic-covered guides show, after strain on belt system (when belt was fastened during accident) fine parallel scoring. (Wear which has been brought about by frequent belt use can be recognized by smooth signs of wear which are free of scoring).
- Inspect for deformation, fracturing and cracks in plastic. Replace seat belt complete with belt latch if scoring and/or damage is determined.
Securing parts and mounting points, checking
- Latch bracket deformed (stretched)
- Height adjustment fitting not working
- Mounting point (seat, pillar, vehicle floor) distorted or thread damaged.
- Replace seat belt complete with belt latch if damage is determined on these parts.
- Replace mounting points.
NOTE: In case of damage which is not result of an accident, but instead by wear (for example), only the part which is actually damaged should be replaced.