Hi, When I apply brakes on my Accord LX Manual, 206K km, the brake padel goes too down and then brakes work. I know the brake pads are pretty new. I talked with mechanic and he said it needs new master cylinder. I have used this mechanic services a few times before like muffler changes, getting heater fan installed etc. and he is basically a used parts seller/mechanic. He is asking 0 for a rebuild master cylinder and installation. I was wondering if its a good idea to have a rebuild master cylinder installed? If yes, is he asking a fair amount? Thank you