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Mercedes-Benz W202 Maintenance: Sealing the Trunk and Fixing the Vacuum Central Locking

 For many enthusiasts, 1990s Mercedes-Benz models represent the peak of the brand's "Golden Era." They are classic, engineering-centric masterpieces with robust engines and clever technical solutions. However, nothing is perfect.

While the W210 and pre-facelift W203 models are notorious for rust issues, the W202 also has its specific corrosion hotspots. And of course, who could forget the classic vacuum-operated central locking system and the inevitable failure of a vacuum pod over time?

In this article, we will cover these two specific issues.


Let's start with rust. Owners of the W202 (specifically the sedan version) may encounter a situation where the trunk starts leaking "out of nowhere." In such cases, the trunk's rubber seal and the metal lip it sits on require immediate attention. Fortunately, a new weatherstrip and some rust converter can save you from a hefty body shop bill if you catch the corrosion in time.

  • Preparation: Remove the trunk floor mat and cover the area with plastic sheeting to prevent flash rust particles, dirt, and chemicals from dripping into the interior.

  • Removing the Trim: Remove the clips from the loading edge cover, then the cover itself. Two types of clips were used (Button style and Recessed style). There are 12 clips in total: 4 in a row (next to the two taillights) and 8 (2-2 next to the lights and 4 in the trunk opening).

  • Clip Design: Both are expansion-rivet types, meaning the clip body goes into the chassis first, followed by the expansion pin which locks it in place.

  • Tools: Use a small flathead screwdriver, string, and a clip removal tool.

 

Button style clip OE: A 201 990 0292 

Recessed style clip OE: A 124 990 0792



A 201 990 0292

A 124 990 0792



 

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  • Cover Removal: Once the clips are out, push the edge cover inward and lift it upward to remove.

  • Pro Tip: Be careful not to lose any clip bodies that might get stuck in the frame. Count them, pair them up, and store them safely until reassembly.

 

Edge cover OE: A 202 690 5825

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  • Seal Removal: Once the cover is off, the weatherstrip is freed. Note that the factory seam of the rubber aligns with the centerline of the trunk lock's fixed part (ensuring the drainage holes on either side are positioned symmetrically at the bottom).

  • Treatment: Pull the seal off the lip and remove it from the car. Treat the exposed (and likely rusty) metal lip with a wire brush, fine sandpaper, and rust converter.

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  • Installation: After the rust treatment, install the new seal. Before fitting, apply a small amount of body adhesive or a thin layer of paint to the lip for extra protection.

 

Trunk seal OE: A 202 750 0198

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  • Reassembly: Reinstall the trim and clips by reversing the disassembly steps.

With that, the rust and seal issues are sorted. Regardless, it’s worth checking back periodically and treating it again if necessary.



Let's get to the vacuum issue now. In my case, the central locking could open the trunk, but upon locking, it would only hiss for about 40 seconds until the vacuum pump shut down to prevent burnout. Replacing the pod is simple in theory but can be time-consuming in practice.

Note: These steps apply to sedan models; the wagon (T-Modell aka S202) solution may differ.


  • Loosen the two 10mm bolts securing the lock to the trunk lid, then pull the mechanism outward.

  • Disconnect the electrical connector (it has a squeeze-release tab on one side).

  • Disconnect the vacuum line. (Tip: Use the wire-cutting section of a pair of pliers to grip the gray connector—do NOT cut it—and pry it outward using the housing as leverage).

  • Separate the vacuum/lock assembly from the latch by releasing two clips and sliding the two elements apart diagonally.

  • Snap the vacuum assembly (plastic frame, pod, linkage, and electrical connection) off the mechanical lock, taking care not to damage the frame or the rods.

  • Once snapped off, the vacuum pod can be slid out of the frame.

  • The linkage connects to the vacuum pod via a pin-and-clip joint. I couldn't disassemble it without breaking the old pod (but since I was replacing it anyway, the important thing was keeping the linkage intact).

  • Attach the linkage to the new pod (it only fits one way).

Vacuum pod OE: A 202 800 2075


A 202 800 2075

 

  • Put the lock mechanism back together based on the previous steps. After reconnecting the (indexed) electrical plug and the vacuum line, guide it back into place—ensuring no wires are pinched—and tighten the 10mm bolts.

  • Torque Spec unknown, so be careful not to strip the threads.

And we are done! Test the operation via one of the door locks (keeping the trunk open for the first test, just in case).

For looking up or verifying part numbers, I highly recommend Partsouq.com, where you can browse the complete parts database for your specific vehicle for free after entering your VIN.

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