For Mercedes-Benz CLK 350 owners, understanding the location and accessibility of vehicle components is crucial for maintenance and repair. When it comes to the fuel filter in the CLK 350 model, specifically those equipped with the M272 engine, it’s important to note a design shift. Unlike some earlier models with externally located fuel filters, the CLK 350 features an internal fuel filter. This means it’s situated inside the fuel tank, integrated with the fuel pump assembly.
This design choice might seem less accessible than an external filter, but it’s still manageable for a competent DIY enthusiast. While replacing an external fuel filter often involves lifting the car and working underneath, accessing the internal filter in a CLK 350 requires interior access. Specifically, you’ll need to work from inside the car, which many find surprisingly straightforward.
The process involves removing the rear seat bottom to expose the access panels that lead to the fuel pump and sender units. Once these panels are removed, you’ll encounter retainer rings securing the fuel pump assembly. Interestingly, there are variations in these retainer mechanisms. Models without California Emissions typically use a screw-type ring that can be unscrewed – often with the aid of a specialized tool, though pliers can sometimes suffice.
However, Mercedes CLK 350 vehicles designed to meet California Emissions standards employ a different system. Instead of a screw ring, these models utilize a large “hose clamp” style retainer. As illustrated in the provided WIS document (http://benzbits.com/w209/FuelPumpLockRing.pdf), this clamp requires a small right-angle tool, such as a SkewDriver, to loosen the screw and release the clamp. Understanding which type of retainer your CLK 350 has is a key first step in any fuel filter or fuel pump related maintenance.
Regardless of the retainer type, safety is paramount when working with any part of the fuel system. Gasoline, while in liquid form is relatively stable, produces fumes that are highly flammable and explosive when ignited. Therefore, any work on the fuel system, including accessing the internal fuel filter of your Mercedes CLK 350, should be conducted outdoors in a well-ventilated area, far from open flames, sparks, or any potential ignition sources. Crucially, always disconnect the vehicle’s battery before commencing any work to minimize risk and ensure safety throughout the process. Taking these precautions will help ensure a safe and successful DIY experience when addressing the fuel system of your Clk 350 Mercedes.
