Seat Belt Systems: Testing and Inspection
Check Points
- Check webbing strap
- Check inertia reel (locking effect)
- Visually check belt latch
- Check belt latch function
- Check belt guides and locking tongue
- Check securing parts and anchorage points
NOTE: If customer refuses to have a damaged seat belt replaced, appropriate note should be made.
Check webbing strap
- Pull belt completely out of inertia reel or lap belt adjustment tongue.
- Inspect belt straps for soiling and, if necessary, wash with mild soap solution.
- If a vehicle has been involved in an accident and any of following damages exist (belt cut, torn or chafed) or (fabric loops at belt edge torn), replace complete seat belt with buckle.
- If a vehicle has not been involved in an accident and exhibits damage as described below, it is sufficient to replace only damaged seat belt.
Possible damages
Belt webbing cut, torn or chafed.
Webbing loops on belt edge torn.
Burn marks from cigarettes or similar.
Belt edge deformed on one side and/or belt edge area is wavy.
Check 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 compete seat belt 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 12 mph (20 km/h) and then carry out emergency braking with foot brake.
- If seat belt is not locked by locking mechanism during braking procedure, complete seat belt with belt latch must be replaced.
CAUTION: For safety reasons, road test should be carried out on traffic-free stretch to ensure that other motorists/pedestrians etc. are not endangered.
Visually check belt latch
- Inspect belt latch for cracks and fracturing.
- If damage is determined, replace complete seat belt with belt latch.
Check belt latch function
Checking latch mechanism:
- Push locking tongue into belt latch until it engages audibly. Check whether locking mechanism is properly engaged by giving belt firm pull.
- If belt tongue fails even only once to engage properly in belt latch during at least 5 tests, complete seat belt with belt latch must be replaced.
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. If belt tongue fails even only once to spring out of latch, complete seat belt with belt latch must be replaced.
CAUTION: Under no circumstances whatsoever may lubricant be used to eliminate noise or stiffness at belt latch buttons.
Check belt guides and locking tongue
After strain on belt system (when belt was fastened during accident), plastic-covered guides show 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.
- If scoring and/or damage is determined, replace complete seat belt with belt latch.
Check securing parts and anchorage points
- Latch bracket deformed (stretched)
- Height adjuster not working
- Anchorage point (seat, pillar, vehicle floor) distorted or thread damaged
- If damage is determined on these parts, replace complete seat belt with belt latch.
- Replace anchorage points.
NOTE: In case of damage which is not result of an accident, e.g. wear, only part which is actually damaged needs to be replaced.
Check Points
- After an accident, child seat anchors must be inspected for damage and deformation.
- Child seat anchors that are welded into body cannot be repaired or connected.
- Child seat anchors that are bolted to body must be replaced if damaged or deformed.