Mercedes does not run a fixed mileage schedule. The car works out what it needs and asks for either Service A or Service B, and the two are genuinely different jobs. Here is what is in each one, what triggers them, and which items are worth not declining.
What Service A includes
- Full synthetic oil and filter change to the Mercedes approval sheet your engine specifies
- All fluid levels checked and corrected
- Tire inflation check and correction
- Brake component inspection
- Reset of the maintenance counter
Worth correcting a common misconception: Service A is an inflation and condition check on the tires, not a rotation. Rotation is worth doing and we will do it, but it is separate work rather than part of the published checklist.
What Service B adds
Everything above, plus two items:
- Cabin dust or combination filter replacement
- Brake fluid exchange
That is the entire difference, and it is why B costs more than A.
Why the brake fluid exchange matters here
Brake fluid is hygroscopic, meaning it draws moisture out of the air through the hoses and reservoir over time. Wet fluid boils at a lower temperature than dry fluid, and fluid that boils produces a pedal that goes to the floor under sustained braking.
In a humid climate that process runs faster. This is the item owners most often decline because it is invisible, and it is the one we would least like you to remove from the list.
How the car decides which one is due
The Flexible Service System, ASSYST on most cars, weighs time, distance and how the car has actually been driven: cold starts, short trips, load and operating temperature. Two identical cars with identical mileage can be asking for different services, which is exactly why a shop working from a mileage chart sometimes performs the wrong one.
We have written up the codes, including the numbered variants like B1, in what your ASSYST PLUS service codes mean.
Does it have to be the dealer?
No. Federal law protects your right to have the car serviced anywhere, provided the work is done correctly and to specification. What matters is that the approved oil goes in, the checklist is actually completed, and the visit is documented. We log every service, so the history stands up if you ever need to prove it.
What it costs
It moves with the engine more than the badge, mostly on oil capacity and which approval sheet applies. We have broken the ranges down in what Mercedes Service A and B actually cost.
For the full checklist and to book, see Mercedes A and B service, or call (561) 392-1910 with your VIN and we will tell you which service your car is asking for.