The reasons for the bulging of automobile brake oil pipe body may include the following points:

1. The internal pressure is too high: the brake oil pipe in the brake system bears the action of high-pressure liquid. If the pressure in the brake system is too high, it may cause the brake oil pipe to bulge. Excessive internal pressure may be caused by bubbles in the brake system, overheating and brake oil expansion.

2. Aging of brake tubing: After the brake tubing is used for a long time, aging may occur, resulting in the hardening and loss of elasticity of the tube material of the brake tubing. The aging brake tubing is prone to bulging when it is subjected to high-pressure liquid.

3. External damage to the brake oil pipe: The brake oil pipe may be hit or damaged by external objects during driving, such as road gravel and roadside obstacles. External damage will lead to the damage of the brake oil pipe body, which will lead to bulging.

4. Improper installation of brake oil pipe: If the brake oil pipe is not installed or fixed correctly during installation, it may be stretched or squeezed unnecessarily, resulting in uneven stress on the brake oil pipe body and increasing the risk of bulging.

5. Brake tubing material problem: Poor quality or improper selection of brake tubing material may also lead to bulging of the brake tubing body. Low-quality brake oil pipe material is easy to deform, expand or rupture, thus causing the pipe body to bulge.

Generally speaking, the causes of bulging of automobile brake tubing mainly include factors such as high internal pressure, aging of brake tubing, external damage, improper installation and material problems. In order to ensure the normal operation and driving safety of the brake system, it is suggested to check and maintain the brake oil pipe regularly and replace the aged or damaged parts in time to avoid the dangerous situation caused by the bulging of the pipe body.