Sinotruk Exhaust Bellows (Flexible Pipe)
The part number for this component is LG9725408020A1.

1. Basic Part Information

• Part Name: Exhaust Bellows / Exhaust Flexible Pipe / Exhaust Manifold Connecting Pipe

• Part Number: LG9725408020A1 (Common part number format for HOWO light truck series such as Tongshuai, Hanjiang, etc.)

• Appearance Features: Silver metal cast or welded structure with a corrugated flexible section in the middle and flanges at both ends for bolted connection. The exterior is typically wrapped with a stainless steel braided mesh sleeve (may not be fully visible in the image, but such parts usually include it) to increase strength and high-temperature resistance.

2. Applicable Models & Installation Position

• Applicable Models: Mainly suitable for Sinotruk HOWO light truck series, such as Tongshuai, Hanjiang, and other models. It may also fit some Sinotruk Wangpai or other light/mini truck platforms.

• Installation Position: Installed between the engine exhaust manifold and the three-way catalytic converter (or muffler). It serves to connect rigid exhaust pipes, providing a flexible connection point.

3. Main Functions & Role

Although the exhaust bellows may seem unremarkable, it plays a crucial role in the exhaust system:

• Vibration Damping & Noise Reduction: The engine generates high-frequency vibrations during operation. The flexible structure of the bellows effectively absorbs and isolates these vibrations, preventing them from transmitting to the muffler or frame downstream, thereby reducing in-cab noise and metal fatigue.

• Compensating for Movement: When the vehicle is driven on rough roads or when the engine undergoes thermal expansion during operation, the exhaust pipe experiences slight displacement and deformation. The bellows compensates for these movements through its own expansion, contraction, and bending, preventing pipe fracture due to excessive stress.

• Ease of Installation: Due to possible minor angular deviations between the engine and exhaust system during assembly, the flexibility of the bellows makes installation more convenient, eliminating the need for extremely precise alignment.