WenmarOpen by Wenmar Pro

Service campaign B340925

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService campaign
NHTSA id11021109
Published by NHTSA2025-07-31
Manufacturer's numberB340925
Manufacturer's date2025-07-30
Campaign id or software version0034200300
NHTSA componentSERVICE BRAKES

NHTSA's summary

There may be an internal leakage in the brake fluid expansion tank (aka brake fluid reservoir). In the rare case of a leak, the filling level sensor might malfunction over a relatively long period of time.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Brakes

Vehicles listed
BMW 330I2024
BMW 430I2024
BMW M22024
BMW M32024
BMW M42024

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
B3409252026-01-05. Service bulletin. There may be an internal leakage in the brake fluid expansion tank (aka brake fluid reservoir). In the rarecase of a leak, the filling level sensor might malfunction over a relatively long period of time.
B3406252025-05-21. Service bulletin. Brake “groaning” noises heard at the rear axle at slow speeds, i.e. close to standstill, stop and go driving;when parking or maneuvering.
B3407142023-11-01. Service bulletin. Functional noises (squealing/honking) when braking shortly before the vehicle comes to a stop. CAUSE Material-