Hi guys, so I’ve got a 1985 Mercedes 200 (2 liter carburetor) and the last month or so the brakes have been giving me a bit of a headache. When standing for a while the brake pedal sinks all the way to the floor, upon some investigation I saw a damaged brake line that I replaced and bled the system, a few days later the problem was back so I bled the brakes again only for the problem to come back after about 2 weeks (It came back slowly but surely, she was my daily in this time) so I went to bleed the brakes again - this time I noticed the rear brakes were fine but the fronts were dry. Passenger side I bled all the air out but the driver side is still bone dry, I checked the connection on the master cylinder and it doesn’t seem like theres any fluid going to that wheel.

I’m only a diy mechanic so I might be missing something obvious but what do you guys recon might be wrong?