Sounds like a sticky master cylinder piston, hayes strokers have had this problem, took my strokers apart twice as both levers were at it, a touch of grease in the bore sorts it, but, the right lever was'nt playing ball so in try it and see, put in and old nine piston as its the same thing and sorted.
Use a grease (unlike me) that does'nt knacker rubber, mine are fine and have been for ages now and during all this, can completely strip and rebuild my brakes now easy peeezie. Should'nt need new brakes for years really.