My 99 E55 has had what I would call 'spongy' brakes since I owned it with 39K miles. Front pads have been renewed and the brakes were bled twice. The dealer replaced the brake booster. I don't lose brake fluid so I thought the Master Cylinder was the last thing to consider. Is there anything I'm overlooking? Do I swap the Master Cylinder next? Thanks for your help JB
1988 300E
1999 E55