The Astros are still searching for managers at Triple-A Oklahoma City and Double-A Corpus Christi, as well as a hitting coach at the Major League level to replace Jeff Bagwell.
Kranitz, 52, spent the past three seasons as the pitching coach of the Orioles and the two seasons prior to that as the Marlins' pitching coach. Florida had the third-best ERA among starters in the National League during the 2006-07 seasons.
"Rick adds a wealth of knowledge and experience to our development system," Astros director of player development Fred Nelson said. "He has a reputation for developing young pitchers and the understanding of what it takes to pitch in the Major Leagues. We are fortunate to have someone of Rick's caliber join our organization."
Sedar, 49, had been the first-base coach for the Brewers for the past four seasons and had previously worked in Milwaukee's Minor League system in several capacities, including as outfield and baserunning coordinator, field coordinator and rookie league manager. He was named the 2003 Pioneer League Manager of the Year after leading Helena to a league-best 48-28 mark.
"Ed is a quality teacher who brings passion and experience to his role as our outfield/baserunning instructor," Nelson said.
Kranitz spent 22 seasons coaching in the Cubs organization, including two seasons (1994-95) as the Minor League pitching coordinator and three seasons (1996-98) as the assistant pitching coach at the Major League level.
Kranitz pitched five seasons in the Brewers' Minor League system (1979-84) after being drafted in the fourth round of the 1979 Draft. The highlight of his career was when he tossed a no-hitter with 14 strikeouts for Class A Stockton in 1981. He replaces Britt Burns, who wasn't retained by the club.
Sedar, a former outfielder, played eight seasons (1981-88) in the Minor League system of the White Sox. He replaces Eric Young, who was recently named first-base coach of the D-backs.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.