I had the same with my 2019 GDI after 11'000 km. On the bottom of the clutch reservoir I found a fine metallic sand (checked with magnet). I suspect these are machining residues that weren't properly washed out of the holes. They destroyed the gaskets of the clutch hydraulic system.
Replaced both: Master cylinder and slave cylinder under warranty of Morgan. Slave cylinder is a Mazda part (NE55-41-92XA). Master cylinder Lockheed LBACBL018AP. Now fine for another 50'000km.
Last edited by SwissMogFan; 25/06/26 12:14 PM.
