Clutch Master Cylinder for Long-Term Cyclic Loading for MERCEDES-BENZ 2042900012

CM246

Application Coverage
This part covers an unusually wide range of Mercedes-Benz platforms — from compact A-Class models to mid-size SUVs — making it a high-utility SKU for distributors managing European vehicle inventory.

Vehicle Model	Platform Code
MERCEDES-BENZ C-Class Saloon	W204
MERCEDES-BENZ C-Class T-modell (Estate)	S204
MERCEDES-BENZ C-Class Coupe	C204
MERCEDES-BENZ E-Class Saloon	W212
MERCEDES-BENZ E-Class T-modell (Estate)	S212
MERCEDES-BENZ E-Class Coupe	C207
MERCEDES-BENZ E-Class Convertible	A207
MERCEDES-BENZ GLK	X204
MERCEDES-BENZ A-Class	W176
MERCEDES-BENZ B-Class	W246 / W242
MERCEDES-BENZ CLA Coupe	C117
MERCEDES-BENZ CLA Estate	X117
MERCEDES-BENZ GLA	X156

OE NO:
A2042900012
2042900012

Core Function
The "cyclic loading" reference points to a real failure pattern that workshops see regularly with lower-grade clutch master cylinders: the part installs fine, performs fine for a few months, then slowly degrades — usually showing up as a soft or spongy pedal, difficulty finding the engagement point, or fluid seeping past the primary cup seal.
The root cause is almost always cumulative internal wear from repeated pressurization and depressurization cycles. Each time the pedal is pressed and released, the piston seal is compressed and relaxed. In a standard cylinder, the seal material and bore finish aren't always built to handle thousands of those cycles without some dimensional change.
This unit addresses that through:
Reinforced piston seal geometry — maintains sealing contact across a wider range of operational temperatures and pressures
Tighter bore surface finish — reduces friction-induced wear during piston travel, extending seal life
Consistent return behavior — piston returns to home position without drift or lateral bias, keeping the hydraulic circuit clean
Stable pedal feel over time — because the internal geometry isn't degrading, drivers notice consistent engagement throughout the part's service life
For workshops, this means the clutch master cylinder doesn't become a repeat repair. For distributors, it means fewer warranty returns on this line item.

Q: Does this part fit all engine variants across these platforms, or only specific configurations?
A: Coverage varies by engine and transmission combination. Please share your full vehicle specification (model year, engine code, transmission type) and we'll confirm fitment before you commit to volume.

Q: What's the MOQ?
A: MOQ varies between standard stock orders and private label configurations. Contact our sales team with your target volume and timeline for a tiered pricing breakdown.

Q: What fluid specification is compatible?
A: DOT 4 and DOT 5.1. DOT 3 is not recommended for European hydraulic clutch systems.

Q: Is private label available without a tooling investment?
A: For standard OEM packaging (box, label, part number), no tooling is required. If you need modified internal specifications under ODM, tooling costs apply depending on the scope of change.