Three bad master cylinders

[grs]

I bought a new Cardon master cylinder. The reservoir leaked. I then exchanged it for another one. It lasted about 1,400 miles then it had an internal bypass leak. The pedal went to the floor. I just put another one on it, and it has a reservoir leak. I will replace it. They are all Cardon with a life time warranty. I have an 87. Anyone else had this problem with Cardon? It has a plastic reservoir on it. Does anyone make one that is all metal? Or who makes one that will last for years, and years the way they should?