The director of ACTION, the federal volunteer agency under fire from congressional investigators, yesterday claimed that his agency had made dramatic advances in all its programs.

ACTION Director Sam Brown, noting recent criticism of him from Congress and about a Peace Corps director he fired, said attacks on him were inevitable, "based on impressions of what I was 10 years ago."

Brown said this might be improved if he were regularly described in newspapers as "former Colorado satte treasurer" rather than "former anti-Vietnam war activist." He said he had spent the last eight years in Colorado involved in politics and broad aspects of community life "and I like to think of myself as more than one-dimensional."

The news conference waa called to amplity on ACTION's rebuttal to allegations contained in a report by House Appropriations Committee investigators. Segments of the report were released Thursday by House Minority Whip Bob Michel of Illinois (R-Ill.)

The report found "apparent weaknesses in ACTION's overall management of its personnel, procurement and budget and finance programs."

Brown renewed his criticism of Michel for violating committee rules in releasing parts of the investigation report. He noted that the committee had planned to let ACTION respond to the report before making any public release.

Brown said some of the problems were arguable, such as a $75,000 joint ACTION-Small Business Administration grant that investigators said was awarded while ACTION was waiting for funding. Brown said ACTION signed the grant on Oct. 28 last year while it had funding, but that the SBA didn't sign it until Nov. 7, by which time ACTION didn't have funding.

The spending was approved retroactively by Congress when it passed ACTION's funding, ACTION general counsel Harry MacLean said.

MacLean also quibbled with the report's findings about political hiring. The report said ACTION had hired 131 such appointees in Brown's first year, compared with 101 in 1976, the final year of his Republican predecessor. MacLean said it should be noted that in the first year of that GOP official, Michael Balzano, there were 200 such people hired.

Those were typical of both the charges and responses. Brown said he found the most serious problems raised involved contract and grants awards, and vowed to clean up any problems be found.

He said his greatest mistakes were in personnel, an oblique reference to his dispute with Carolyn Payton, whom he fired last months as Peace Corps director.