The Educational Political Action Committee, a well-known Montgomery County education coalition, gave its endorsement last week to four candidates in this fall's Board of Education elections.

But in one of the most peculiar episodes in the school board races this year, three of the 13 candidates, including one of EDPAC's founders, spurned the endorsements before they were made.

The three candidates are James E. Cronin, an incumbent running at large; District 3 candidate Vicki Rafel; and District 5 candidate Bea Gordon. They issued a joint statement this month, denouncing EDPAC and its endorsement method.

The three have not formed a slate, but they share views on EDPAC, according to Rafel, who helped to form the coalition in 1981. EDPAC was founded to try to replace conservative board members, who held a majority in the late 1970s and early 1980s.

The three candidates contend that the group no longer represents a cross-section of community opinion. "The focus of the group has become less clear," Rafel said in the joint statement.

In addition, Cronin contended in the statement that the group's endorsements were "pre-determined" last February, before most candidates had even filed for the fall elections. Keith Prouty, EDPAC's president, said, "I was astounded" to learn of the complaints. "The allegation that the endorsements were predetermined is absolutely untrue."

But he acknowledged that the four candidates the group chose to support were among the residents that he had urged to run for the board.

The candidates who won endorsements are Alan Cheung in the at-large race, Carol Franconi in District 1, Ana Sol Gutierrez in District 3, and Don Buckner in District 5.

In making its endorsements, EDPAC considered candidates' policy-making leadership; ideas for improving teaching; commitment to educating a diverse student body, including minorities; support for science and math education; and experience with public education. Other Endorsements

The Central Committee of the Montgomery County Republican Party nominated candidates last week to fill vacancies in four state legislative races. According to the Board of Elections, the candidates, whose names will only appear on the general election ballot in November, are Thomas R. Falcinelli, for the District 20 state Senate seat, and House of Delegates contenders: George Jenkins, District 16; David S. Green, District 17; and Jamie M. Staines, District 18. There will be no Republican primary run-offs in these races. -- Veronica T. Jennings