Hello, i noticed my original lockheed servo was leaking, so instead of repairing i thought id just replace. i went for an uprated "Powertune" replacement off ebay. Am i missing something or are these just rubbish? i've bled and bled it through the old fashioned 2 people method, i've even tried releasing the unions on the servo too but it's always the same. The breaks whilst not spongy seem to stick when pressing the pedal. poor braking until you really press hard then you lurch forwards from sharp braking. if you give them a little pump then re apply they work quite well. you can also feel the brakes just momentarily sticking on for a second after you release your foot. i've been through the calipers, they're fine and every rubber pipe has been replaced too. This has all only happened since the servo change. I had the same story years ago with another standard Powertune servo. so i'm thinking it must be me!! Car is a 1970 Mk1 P6 2000 sc auto. Many thanks.