Is Mercedes Benz Service B Necessary?

This blog will answer the following questions: Is Mercedes Benz Service B Necessary? What are the different tasks performed in service B of Mercedes Benz? How much does service B cost in Mercedes Benz? 

Is Mercedes Benz service B necessary?

Yes, Mercedes Benz service B is necessary because it is a major service of the vehicle and usually consists of additional checks of the braking system, suspension system, tires, and fuel system. Service B ensures the vehicle is running in optimal condition. The cost and time required for service B are also more than service A. Standard or extended warranty claims can be rejected if service B is not performed.

The service interval in Mercedes Benz is 10,000 miles or 1 year for service A and 20,000 miles or 2 years for service B. when the service due date is within one month, the Assyst plus service computer will display the service due message depending on the previous service record.

The service due message does not reset unless the service is confirmed through the instrument cluster or diagnosis tool. It is possible to check the previous service records in the Assyst Plus memory.

A workshop code is also generated and the service technician can retrieve it from the instrument cluster. The workshop code determines the number of the service, for example, service b2,b4,b6, or b8. The checksheets and the scope of the work can also be generated from the workshop code.

What are the different tasks performed in service B of Mercedes Benz?

The different tasks performed in the service B of Mercedes Benz cars are explained below:

  • Engine oil and oil filter change

Mercedes Benz uses fully synthetic engine oil but the properties of the engine oil deteriorate with the age and mileage of the vehicle. Hence, the old engine oil is drained and the engine oil filter is also replaced in service B.

On the engines with plastic oil pans, the engine oil drain plug is also renewed, and service B also includes a visual inspection of the engine. Engine oil is not replaced if an external engine oil leak is identified from the engine.

If the drained quantity of the engine oil is less or more than the specified quantities then further checks are required to check for an internal leak or excessive engine oil consumption. The condition of the oil filter is also inspected, if there are too many metal particles in the oil filter and oil filter body then it can indicate excessive wear of moving components due to incorrect tolerances.

  • Air filter/ Combination filters

The air filters are replaced in service B of the vehicle; diesel engines operate in an excess amount of air. Hence, there is too much dust in the air filters of diesel engines by the time the vehicle reports for service B.

Similarly, the combination filters are also replaced in service B. Customer complaints like bad smell from the AC can arise if the combination filter is not replaced. The airflow can even get restricted if the air conditioning filter is completely blocked.

  • Inspection of the steering system

A visual inspection of the steering rack is performed, the steering wheel is operated end-to-end and the condition of the steering rack boot is checked. If the vehicle has a hydraulic steering rack then the power steering fluid level is also checked.

Any cuts or damage to the steering boot is documented and a separate estimate is provided to the customer to rectify the damaged boots or any hydraulic leak.

  • Inspection of the suspension system

When the vehicle is lifted on a lift all the suspension components are checked for any damage. The shock absorbers can bend if there is a hard impact. Ball joints, control arms, and subframe bushes are also accessed for any cuts that can lead to abnormal noises or handling issues.

All the findings are documented and reported to the customers, if any damaged suspension components are observed the service writer or advisor can recommend a further course of action. 

  • Inspection of the brake system

The brake pad thickness is measured with the help of a depth gauge. The brake wear sensor will activate at 2-3 mm thickness. Hence, if the actual thickness is closer to the minimum thickness then it is recommended to replace the brake pads.

Similarly, the brake discs or rotor thickness is measured with the help of a vernier caliper. According to the model and type of the rotor used, Mercedes Benz has specified the minimum thickness of the brake discs.

The brake discs are also visually inspected for damage or excessive runout. Mercedes Benz uses different types of brake systems so the procedure to access the condition can vary according to the brakes. For example, the ceramic brake system uses a special tool to check the carbon content of the disc.

The brake fluid is also replaced in service B, a brake fluid tester is used to determine the moisture content in the brake fluid. If there is excessive moisture, then the brake pedal can feel spongy.

  • Automatic transmission fluid

It is replaced in the service B4 or 40,000 miles. The automatic transmission oil filter is also renewed along with the entire oil pan or oil pan gasket. Mercedes Benz automatic transmissions are not sealed-for-life.

Replacing the automatic transmission fluid can take more time because the fluid level is checked at 45 degrees. It takes time for the automatic transmission oil to reach the specified temperature as the vehicle is at a standstill.

The quantity of the automatic transmission fluid depends on the type of transmission and the cost of service B can increase if there is 9 G-Tronic transmission. The transmission oil filter of the 9 G Tronic is integrated into the oil pan so all the complete oil pan must be replaced during service B.

  • Spark plugs and fuel filters

The spark plugs in the Mercedes Benz with gasoline engine are replaced at B4 is part of the preventive maintenance as a faulty spark plug can lead to a breakdown. The fuel filters in the diesel Mercedes Benz are also replaced at every service B.

If the fuel filter is not replaced, the fuel pressure in the high-pressure fuel system will drop and the engine check light will come on.  Blocked fuel filters can even lead to the engine not starting.

How much does service B cost in Mercedes Benz? 

The cost of service B in Mercedes Benz starts at 400 USD but the overall can go up to 600 USD depending on the age and mileage of the vehicle. Mercedes Benz also offers service packages that can reduce maintenance costs significantly.


This blog explained the various service operations carried out in Service B of Mercedes Benz. The service type and interval are determined by Mercedes Benz so that the vehicle stays in good condition. If service B is not performed then the performance of the vehicle will deteriorate and it will break down.