Why won't my Mercedes CLK convertible top work?
Likely causes, ranked
- Bad pump relayDIY
- Low fluid from leaking cylindersShop
- Weak batteryDIY
Real-owner fix counts will appear here as reports come in.
DIY or shop: See DIY or shop section
Parts to check
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Short answer: The W209 CLK cabriolet's top runs on a hydraulic pump. When the top stops working, owners have found bad pump relays, blown fuses, low fluid from leaking cylinders, and weak batteries. Check the cheap things first.
Symptom: The top won't open or close, the pump doesn't run, or it stops partway.
What to check first
- Check the 40A fuse and swap the pump relays.
- Check the hydraulic reservoir. Empty means a leak.
- Check the battery.
- Look for leaks at the lift cylinders.
Likely causes
- Bad pump relay.
- Low fluid from leaking cylinders.
- Weak battery.
What it usually costs
Owners in these threads didn't post repair prices.
Is it safe to keep driving?
Yes, if the top is fully closed and latched. Verify with a mechanic.
DIY or shop?
DIY for fuses and relays. Cylinder rebuilds are shop or specialist jobs.
Recalls, bulletins and complaints in plain words
- Recalls: NHTSA's recall lookup returned an error for the Mercedes CLK for 6 model-year queries on 2026-10-22, so we couldn't confirm recalls here. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
- NHTSA complaints: 42 keyword-matched complaints for Mercedes CLK 2004–2009 (of 201 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-22; keywords: top, convertible, roof, hydraulic). This counts complaints that mention these words. It is not a defect finding.
What owners report
- In this MBWorld thread, the pump wouldn't run in the open direction. Swapping the pump relays fixed it; members also said to check a 40A fuse.
- In this MBWorld thread, a 2004 CLK320 owner's reservoir was empty because the main lift cylinders leaked. Members said there are seven cylinders and a weak battery can stop the top.
Quick tip
Swap the relays first. It's free and it worked here.
Vehicle focus: 2004–2009 Mercedes-Benz CLK cabriolet (W209/A209).
Safety / mechanic note
A moving top can trap hands. Hydraulics are under pressure. Verify with a mechanic.
Recalls & service bulletins
No recalls or service bulletins are listed for this page yet.
NHTSA complaints: 42 keyword-matched complaints for Mercedes CLK 2004–2009 (of 201 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-22; keywords: top, convertible, roof, hydraulic).
Always check your VIN for open recalls at nhtsa.gov/recalls.
Sources
What actually fixed it?
Had this problem? Tell other owners what the real fix was. Reports are counted above; we never show made-up numbers.