Yes , be careful most new cylinders are step type . They would have to be changed in pairs and will use a little more fluid ,hence may lower pedal .  You talk about a firm pedal is it braking good . Found you'll get hard pedal as hoses collapse and prevent fluid return . I say sleeve also  Hagens Hwy  Auto does great work .

Had similar problem this year . was coarse rust in tank restricting fuel flow . But not making to fuel filter to show up. Top of tank was rotting away ,more I drove worst it got .