What Is Included in Mercedes Service B1?

Mercedes-Benz maintenance schedules can feel confusing at first, especially when you start seeing variations like Service A, Service B, B1, B2, B5, and so on. While Service A and Service B are the two main recurring maintenance packages, the numbered subcodes (like “1” in B1) indicate additional tasks or inspections specific to your vehicle’s mileage, condition, and the onboard maintenance system’s assessment.

Service B1 is a combination of the main Service B interval plus a “1” sub-service, which targets an additional system—usually related to braking components. Although exact requirements can vary slightly depending on model and year, the core structure of Mercedes Service B1 is quite consistent across most modern vehicles including the C-Class, E-Class, GLC, GLE, S-Class, CLA, GLA, GLS, and similar platforms.

This guide provides a detailed, in-depth explanation (1,200+ words) of everything included in Mercedes Service B1, what each step means, why Mercedes uses subcodes, how dealerships and independent shops perform this service, how much it typically costs, how long it takes, and tips for saving money while still keeping your vehicle in top condition.

What Is Service B in General?

Before diving into the “B1” specifically, it helps to understand what the base “Service B” includes. Mercedes-Benz uses a flexible maintenance system called the ASSYST Plus or an updated service counter depending on your model year. This system monitors engine hours, temperature, oil quality, and time/mileage to determine when specific services are needed.

Service B usually occurs around 20,000 miles or 2 years after your last service interval—but this can vary depending on driving conditions and model year. Service B is more detailed than Service A and includes deeper inspections and more maintenance checks.

A standard Service B typically includes:

• Oil and filter replacement using Mercedes-approved synthetic oil
• Cabin dust/combination filter replacement (for air quality)
• Brake fluid replacement (every 2 years on many models)
• Tire inflation check and correction
• Brake component inspection
• Fluid level checks (coolant, windshield washer, power steering, etc.)
• Resetting maintenance counter
• Multi-point inspection of major systems
• Suspension, steering, and chassis visual checks
• Lights, wipers, and instrument system inspection

Now, when a “1” code is added, it means a specific additional service is required during that B-service visit.

What Does the “1” in Service B1 Mean?

Mercedes uses numbers attached to service intervals to denote additional tasks. A “1” sub-service usually means a focus on a particular mechanical area—most commonly related to brake components.

Although Service B1 can slightly vary by model, the “1” subcode typically indicates:

• Brake inspection and/or brake pad replacement assessment
• Inspection of brake hoses and lines
• Evaluation of brake fluid condition (though fluid replacement is already part of main Service B in many models)
• Parking brake function inspection

In many cases, the “1” designation does NOT automatically mean your brake pads will be replaced—it means the inspection required is specific and must be documented, and pads will be replaced only if wear indicators show they are below Mercedes specifications.

Now, let’s break down the full list of tasks included in Mercedes Service B1.

What Is Included in Mercedes-Benz Service B1?

Service B1 = Standard Service B + Subcode 1 Brake-Related Service

1. Synthetic Oil Change & Filter Replacement

Mercedes engines require full-synthetic oil that meets the manufacturer’s approved specifications (often MB 229.5 or 229.51 depending on the engine). During Service B1, the technician drains the old oil, installs a new OEM-quality oil filter, and adds fresh oil.

This ensures proper lubrication, lower engine wear, and correct turbocharger function (especially important for modern Mercedes engines).

2. Cabin Air Filter Replacement

As part of the standard Service B, Mercedes includes replacing the combination cabin filter (sometimes called the dust/charcoal filter). This helps maintain proper airflow and ensures clean air for the HVAC system. It also helps prevent fogging and keeps contaminants out of the cabin.

3. Brake Fluid Change (Usually Included in Service B)

Most Mercedes models require a brake fluid flush every 2 years. Brake fluid absorbs moisture from the air, which can reduce braking performance and corrosion resistance. During B1 service, the fluid is replaced by bleeding the old fluid out and adding fresh DOT4 brake fluid.

4. Full Brake System Inspection (Subcode “1” emphasis)

Here’s where the “1” sub-service becomes important. The technician will perform a thorough inspection of:

• Front brake pads
• Rear brake pads
• Brake rotors
• Brake hoses and hydraulic lines
• Brake wear sensors
• Parking brake mechanism (electronic or mechanical)

The technician will take measurements of pad thickness and rotor wear, ensuring they meet the minimum Mercedes specifications. If they are worn, the service advisor will recommend replacement. In many cases, owners who are close to needing pads soon benefit from doing it during their B1 service visit.

5. Tire Pressure Adjustment & Inspection

All four tires (and sometimes the spare if applicable) are inspected for:

• Correct inflation
• Tread wear pattern (which also indicates alignment condition)
• Sidewall condition
• Tire age

6. Multi‑Point Vehicle Inspection

Mercedes technicians perform an extensive systems inspection, which typically covers:

• Exterior lights, brake lights, turn signals
• Windshield wipers and washer system
• Engine belts and pulleys
• Hoses and clamps
• Coolant level and condition
• Transmission fluid level (model-specific)
• Power steering system (if equipped; many newer Mercedes use electric steering)
• Suspension bushings, arms, ball joints, and components
• Exhaust system condition
• Battery health and charging system test

7. Checking & Topping Up All Fluids

During a B1 service, technicians check or top up:

• Coolant/antifreeze
• Power steering fluid (if applicable)
• Windshield washer fluid
• Differential fluid on some models
• Transmission fluid (visual only unless leaking or malfunctioning)

8. Resetting the ASSYST Maintenance Counter

Once service is complete, the technician resets the onboard service indicator. This allows the car to correctly track your next service interval and ensures accurate maintenance reporting.

9. Software Updates (If Required)

Many Mercedes dealers check for:

• ECU updates
• Transmission software updates
• Safety system calibration updates
• Infotainment firmware updates

These are not always part of independent shop routines, but dealers often include them during a B1 visit.

How Long Does Service B1 Take?

Most Service B1 appointments take around:

• 1.5 to 2.5 hours at a dealership
• 1 to 2 hours at an independent shop

This depends on whether brake pads or rotors need replacement, whether additional recommended services are performed, and how busy the service center is.

How Much Does Mercedes Service B1 Typically Cost?

Costs vary widely by region and whether you choose a dealer or an independent shop, but typical pricing is:

• Dealer price: $450–$850+ depending on model and brake-related needs
• Independent shop price: $250–$600 on average

If brake pads or rotors are replaced, expect additional charges (anywhere from $200–$1,000 depending on OEM vs aftermarket and front/rear replacements).

Do You Have to Do Service B1 at a Dealer?

No. As long as:

• Proper fluids and parts are used
• A qualified mechanic signs off on the work
• You keep receipts and documentation

Your warranty and maintenance schedule remain valid.

Final Summary of What Service B1 Includes

Mercedes-Benz Service B1 is a comprehensive maintenance interval that includes the full Service B package plus an additional brake-focused inspection indicated by the “1” subcode. The service covers oil and filter changes, brake fluid flushing, cabin air filter replacement, fluid checks, system inspections, software updates, and a detailed brake system assessment.

It is an essential service for vehicle longevity, safety, and reliability. Whether you choose a dealership or a trusted independent specialist, completing Service B1 on time helps maintain both performance and resale value.

If you want, I can also create a comparison for B1 vs B2 vs B5 or give you model-specific Service B1 checklists (C‑Class, E‑Class, GLC, etc.).