Judith Johansen Rush, 51, a Congressional aide from 1956 until 1974, died Tuesday in the Florida Hospital in Orlando, Fla., following a series of strokes.

Mrs. Rush moved to Washington about a year after her father, former Rep. August E. Johansen (R) took his seat from Michigan's 3rd Congressional District, which includes Battle Creek.

She worked for Rep. Charles B. Brownson (R-Ind.) from 1956 to 1959. She worked briefly on the staff of Rep. F. Bradford Morse (R-Mass.) and then joined the staff of Rep. William E. Minshall (R-Ohio) and remained there until 1974. She was a speech-writer as well as an administrative aide.

In 1974, she moved to Winter Park, Fla., and lived there until her death.

Mrs. Rush was born in Oak Park, Ill., and grew up in Battle Creek, Mich.

Her marriage to William Blackmore ended in divorce. Her second husband, Phillip D. Rush, a former freelance photographer in Washington, died in 1976.

In addition to her father, of Winter Park, survivors include a daughter by her first marriage, Ann Pichette, of Delaware City, Del., and three sisters, Mrs. Thomas L. Higby of Poulsbo, Wash., Mrs. John A. Beckett of Ridgewood, Conn., and Mrs. Mary Buckler of Wheaton.

The family suggests that expressions of sympathy be in the form of contributions to the Critical Care Unit, Florida Hospital, Orlando, Fla. c