Brake master cylinder

Got a spongy clutch pedal and noticed some fluid leaking into footwell, I take it my master cylinder is gone? Any advice on changing one of these much appreciated. Ps where is the fluid reservoir? Thanks in advance

Check it's not the heater matrix leaking onto the footwell carpet - common fault if it's not been changed previously.

Does your clutch pedal sink to the floor while stationary but when you lift it back up with your foot it maintains pressure? If so that's probably the master cylinder and it's awkward to get at.

If the pedal falls flat to the floor think slave cylinder - accessed under battery tray.

The reservoir is against the firewall and it serves both the brakes and clutch.

Definitely clutch fluid leaking out. When I put foot on pedal it goes to floor and slowly returns when I lift off, can only just change gear now. When I replace will I have to bleed the brakes as well? Never changed one of these before so a bit green. Thanks for the info so far 👍👍

Sounds like master cylinder - the internal seal goes but isn't always associated with actual fluid loss, though it sounds like it's a possibility in your case.

If your windscreen has collected a film over the inside which is difficult to clear I would still investigate the heater matrix.....