The retractable hardtop is the SLK's defining feature and its most-discussed failure point. The R170 system uses five hydraulic cylinders whose factory seals are considered substandard; a leaking front latching solenoid can soak the (now-NLA) headliner in fluid. …
Folding hardtop hydraulics: five cylinders, weak seals, Top Hydraulics fix
Mercedes-Benz SLK / SLC · mechanical