Seat belts are the first line of defense in protecting vehicle occupants during a collision.
During an accident, seat belts undergo extreme tension, rapid locking, and often pretensioner activation.
Even if the belt looks normal on the surface, internal components may have already been damaged.
For this reason, global safety standards and automotive manufacturers recommend replacing any seat belt involved in a collision.
When a crash occurs, the seat belt system experiences:
Instant locking of the retractor
High load on the webbing (up to 6–10 kN)
Activation of the pretensioner (if equipped)
Thermal and mechanical stress
Possible tearing or stitching deformation
Even if these issues are invisible, internal components may no longer function safely.
If the vehicle is equipped with a pretensioner:
The pyrotechnic device fires once only
The internal wire, ball gear, or piston system becomes locked
The belt cannot reset to its original state
Reusing it compromises safety
Crash forces can cause the webbing to:
Permanently stretch
Lose elasticity
Suffer micro-tears or heat damage
Become unsafe in the next accident
Such damage is often invisible, but drastically reduces performance.
Under crash load, the retractor:
Experiences sudden locking
Applies high stress on gears, springs, and locking pawls
May become partially functional or fail later
A faulty retractor may not lock properly in another emergency.
Most automotive guidelines require mandatory replacement of seat belts after deployment or crash involvement.
Relevant standards:
FMVSS 209 / 210 (USA)
ECE R16 (Europe)
GB 14166 (China)
Vehicle manufacturers like Honda, Toyota, Ford, Nissan, Hyundai, GM also specify:
“Any seat belt assembly that has been in use during a crash must be replaced."
| Symptom | What It Indicates | Risk |
|---|---|---|
| Pretensioner Fired | Pyrotechnic unit used | Cannot be reused |
| Belt Cannot Retract Fully | Retractor spring damage | Weak or failed locking |
| Airbag Light On (SRS Code) | Fault detected in seat belt circuit | Safety system not functional |
| Stitching Deformed | Webbing experienced overload | Webbing may break |
| Webbing Feels Loose | Permanent stretching | Reduced occupant restraint |
Even if the belt looks “fine," internal components may already be compromised.
A complete safety repair usually includes:
| Component | Replace? | Reason |
|---|---|---|
| Seat Belt Assembly (Retractor + Webbing) | ✔ Yes | Contains locking and load-bearing components |
| Pretensioner | ✔ Yes | Single-use pyrotechnic device |
| Buckle with Sensor | ✔ Recommended | Load stress may damage sensor |
| SRS Control Module | ✔ Reset or replace | Stores crash data |
| Airbags (Driver / Passenger) | ✔ If deployed | Must be replaced |
Proper replacement ensures full functionality of the vehicle’s SRS system.
Failing to replace accident-involved seat belts may cause:
Failure of belt locking in the next emergency
Webbing tearing during a collision
Airbag system malfunction
Increased injury or fatality risk
Liability issues for repair shops or vehicle owners
A malfunctioning belt can make even a mild accident life-threatening.
Seat belts are engineered to withstand a single major collision.
Once they experience a crash, they cannot guarantee the same level of protection again due to structural damage and pretensioner activation.
For maximum safety, compliance, and peace of mind:
Any seat belt involved in an accident must be replaced with a new, certified assembly.
Andaotong provides OEM-grade replacement seat belts for Asian, American, Middle Eastern, Germany, and Latin American vehicle models, like:
Honda / Toyota / Nissan / Hyundai / Kia
Ford / Chevrolet / Dodge / Jeep
Mitsubishi / Mazda / Subaru