According to Au7o's analysis of 3,700+ owner reports, the 2004 Mercedes-Benz SL-Class has 2 documented known issues, with 1 rated critical. The most serious is ABC (Active Body Control) Hydraulic System Leak ($1,500-$5,000 repair). The most commonly reported issue is ABC (Active Body Control) Hydraulic System Leak with 2,200 owner reports. Across all issues with published estimates, repair costs range from $800 to $5,000. DIY maintenance guides at au7o.io.
On the 2003-2012 Mercedes-Benz SL-Class, the Active Body Control hydraulic suspension on R230 SL models is notorious for developing high-pressure hydraulic leaks at the struts, lines, and pump. The system operates at 3,000 PSI, and even small leaks result in rapid fluid loss and suspension failure. Leaking fluid can damage other components and create fire risk on hot exhaust components.
Identify and replace the leaking component — struts, hoses, pump, or valve blocks. Use only Mercedes-approved Pentosin CHF 11S hydraulic fluid. Consider converting to conventional coilover suspension if repair costs become prohibitive — several kits are available for the R230.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
VIN-confirmed ABC refill and bleeding after the exact leak or component repair Fitment/availability: The inspected direct U.S. Confirm code 487, reservoir
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Owner tips & cautions
WarningABC system repairs are the single most expensive ownership cost on the R230 SL. Budget $1,500-$5,000 per repair. Some owners spend $10,000+ over ownership on ABC alone. Coilover conversion kits from Arnott or BC Racing eliminate the problem permanently.
High Confidence2,200 owner reportsLast reported by owners Dec 2025Reviewed Mar 2026
Community reported
1,500 owners
On the 2003-2020 Mercedes-Benz SL-Class, the Vario Roof retractable hardtop system on both R230 and R231 SL models develops hydraulic cylinder leaks, pump failures, and microswitch faults that prevent the top from opening or closing. The complex system uses multiple hydraulic cylinders, position sensors, and a controller that all must function in sequence. Any single component failure stops the entire operation.
Diagnose with Star Diagnostics to identify the specific failed component in the sequence. Common failures include the hydraulic pump, roof lock actuators, and microswitches. Hydraulic fluid level should be checked and topped off. Replace only the failed component rather than the entire system when possible.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
Genuine Mercedes Vario Roof hydraulic oil 000989020609
OEMMercedes-Benz A000989020609 / MB 346.0
Post-repair refill and bleeding of the R230 or R231 Vario Roof hydraulic circuit Fitment/availability: Mercedes operating-fluid sheet 346.0 lists A0009890206 for R230 and R231 roof hydraulics. The inspected direct U.S.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
TipNever force the top if it stops mid-cycle. Let it return to its starting position and diagnose the fault. Forcing it can bend the mechanism and turn a $500 repair into a $4,000 one.
What are the most common Mercedes-Benz SL-Class problems?
According to Au7o's analysis of 3,700+ owner reports, the 2004 Mercedes-Benz SL-Class has 2 documented issues. The most frequently reported are: ABC (Active Body Control) Hydraulic System Leak, Retractable Hardtop Hydraulic System Failure. Of these, 1 is rated critical and should be addressed promptly.
Is the Mercedes-Benz SL-Class reliable?
The 2004 Mercedes-Benz SL-Class has 2 known issues documented across 3,700+ owner reports. 1 issue is rated critical: ABC (Active Body Control) Hydraulic System Leak. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Mercedes-Benz SL-Class problems?
Repair costs for known Mercedes-Benz SL-Class issues range from $800 to $5,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, ABC (Active Body Control) Hydraulic System Leak, typically costs $1,500-$5,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2003-2012 Mercedes-Benz SL-Class ABC (Active Body Control) Hydraulic System Leak?
The Active Body Control hydraulic suspension on R230 SL models is notorious for developing high-pressure hydraulic leaks at the struts, lines, and pump. The system operates at 3,000 PSI, and even small leaks result in rapid fluid loss and suspension failure. Leaking fluid can dam… Repairs typically run $1,500-$5,000. Severity: high.
What is the 2003-2020 Mercedes-Benz SL-Class Retractable Hardtop Hydraulic System Failure?
The Vario Roof retractable hardtop system on both R230 and R231 SL models develops hydraulic cylinder leaks, pump failures, and microswitch faults that prevent the top from opening or closing. The complex system uses multiple hydraulic cylinders, position sensors, and a controlle… Repairs typically run $800-$4,000. Severity: medium.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
