A federal appeals court yesterday reversed itself and upheld a Reagan administration petition to expand the recall authority of the Environmental Protection Agency in emissions defects cases.

By an 8-to-3 vote, the U.S. Court of Appeals for the District of Columbia said the EPA may recall cars that have more than five years or 50,000 miles of use. The ruling by the full court overturns a 2-to-1 decision last December by a three-judge panel.

The EPA, through an administrative ruling on May 30, 1980, had sought to expand its recall authority to include all affected vehicles, "regardless of their age or mileage." The agency ruling was issued in a case involving 200,000 General Motors Corp. Cadillacs manufactured for the 1975 model year.

The appeals court panel originally ruled that the EPA regulation went "well beyond simple statutory interpretation" of the "useful life" provision of the Clean Air Act.

The act defines "useful life" as "a period of use of five years or 50,000 miles (or the equivalent), whichever first occurs."

Circuit Judge Patricia M. Wald expressed the minority opinion in the ruling last year, saying that it "effectively guts" the EPA's recall authority under the Clean Air Act.

But Wald wrote the majority opinion yesterday after an April reargument of the case before the full court.

The "useful life" provision of the Clean Air Act does not exempt "older members of a recall class" from EPA action, Wald wrote. She said that the agency's interpretation of the law "makes good practical sense because, no matter what their age at the time of the recall, nonconforming cars have been riding the roads in violation of pollution standards."

The EPA "may reasonably require manufacturers to include older cars and engines in their plans to 'remedy the nonconformity' of the class," Wald wrote.

Senior Circuit Judge David L. Bazelon wrote the minority opinion. "The interpretative rule upheld by the court today enjoys the virtues of simplicity, administerability, and apparent congruence with powerfully attractive ideals of public policy," Bazelon said. "Regrettably, however, it suffers from the vices of administrative overreaching and a marked incongruence with the language and history of the statute it purports to interpret."

GM officials yesterday said they are "disappointed in the decision" of the majority. They said the company's lawyers "would have to read the full opinion to see what options are available to us."

EPA officials, however, were elated. "We're pleased as punch," an agency spokesman said. "We feel that today's decision is very important to the . . . recall program. The previous decision would have rendered the program ineffective."