Brake failure is a very terrifying problem, especially during driving. Once the brake fails, the consequences will be unimaginable. When it comes to the causes of trailer brake failure, the first thing that car owners think of may be air circuit faults, abnormal wear of brake pads/drums, damage to valve bodies, overheating of brakes, severe overloading, etc. In fact, there are many reasons for brake failure, some of which are even unexpected, such as lubricating grease.

Lubricating oil is a necessity on the wheel end. Ordinary axles generally use lubricating grease, while maintenance-free axles commonly use lubricating oil, which plays a role in lubrication, rust prevention, corrosion prevention, and wear prevention. It can protect parts, reduce the frequency of parts replacement, and extend the service life of parts.

But once it enters the brake drum, it will stick to the inner wall of the brake drum and the brake pads. As the two come into contact, the adhesion area becomes larger and larger, and the originally dry brake pads will also become abnormally wet and slippery, resulting in braking stagnation, excessive braking distance, abnormal braking system noise, and other phenomena. In severe cases, it will cause braking failure and affect driving safety.

So, why does the good lubricating grease get into the brake drum? The main culprits are the following two:

1. Add excessive lubricating grease to the wheel end.

Some car owners, when performing wheel end maintenance, believe that adding more lubricating grease is not harmful, but also beneficial for lubrication and prolongs the next maintenance time. Therefore, they add more lubricating grease than the specified amount.

Excessive grease can lead to an increase in pressure on the sealing element, resulting in an unstable seal. The filling amount of grease increases linearly with the bearing temperature. Excessive grease can easily cause excessive bearing temperature, further exacerbating the aging and damage of the sealing element.

So when applying wheel end lubricating oil, car owners should avoid excessive use and do not exceed the sealing capacity of the oil seal.

2. There is a problem with the wheel end oil seal.

The oil seal is located between the braking system and the bearing, and its main function is to isolate the lubricating oil on the bearing to prevent it from entering the braking system. In general, oil seals are often designed for long-term maintenance or maintenance free, and their service life is relatively long. However, if the cooling measures of the vehicle's braking system are not appropriate, resulting in frequent high temperature conditions at the wheel end, it will exacerbate the aging of the oil seal and cause oil leakage.

Therefore, car owners should take cooling measures at the wheel end during the driving process, especially those who frequently travel to and from mountainous areas. If the budget is sufficient, it is best to install auxiliary braking systems such as hydraulic retarders. If the water shower is not disabled in the area, a water shower cooling device can also be installed. Although it does not have an advantage in weight and is not in line with market trends, its effect on drum brake cooling is still quite obvious.

In addition, during daily transportation, car owners should remember to keep their vehicles "three separate and seven separate maintenance". Regular vehicle inspections and maintenance should be carried out based on their own operating conditions. Even for maintenance free axles, they must not only operate them without maintenance, especially for the braking system. They should also take preventive measures.

Common brake system faults and solutions:

1. Partial braking. At the moment when the vehicle approaches a stop, the steering wheel will always deviate to one side to a greater or lesser extent. The main reason for this phenomenon is that the force on the left and right cylinder of the braking system is uneven, and the cylinder needs to be replaced in a timely manner.

2. The brake does not return. In this case, it is possible to check whether the return spring/brake caliper is damaged, whether the brake fluid is missing, whether there is oil leakage at the brake wheel cylinder/pipeline and joints, and whether components such as the master cylinder/wheel cylinder are damaged.

3. The car shakes when braking. It is generally caused by eccentric wear and uneven surface of the brake drum or brake disc. It is recommended to replace the brake drum or brake disc with a new one.

4. Brake deviation. During emergency braking, the vehicle cannot decelerate in a straight line, possibly due to significant differences in tire pressure or wear, excessive brake clearance between the left and right wheels, and different braking torques.

5. The braking force can only be provided after the car is hot. After the vehicle starts, it is unable to immediately apply braking force. This situation is mainly due to a loss of pressure in the pressure transmission pipeline. It is possible to check whether there are cracks or looseness at the interface between the vacuum booster pipe of the lower master cylinder and the engine.

Of course, to ensure the safety of vehicle braking, it is also important to choose a high-quality axle, especially for trailers that frequently run heavy loads. It is still necessary to choose a trailer specific axle, which fully considers the use environment and needs of the trailer. It is stronger, more wear-resistant, has higher thermal capacity, and is not prone to softening or deformation.