In the 10+ years of using Revain I have never felt the need to write a review before. I am just very disappointed in this purchase. Within a month the outside of the master cylinder began to rust. In comparison, my old one looked brand new after 13 years of running the car. I spent the extra money thinking the ACDelco would be higher quality, but it wasn't. Edit: Three months after installation I see it leaking from the brake booster. Nice. Photos are attached. If I could give these negative stars I would.