At 7:10 this evening a covered pickup truck passed through the gate of Bicutan military camp and five political prisoners seated in the rear among friends and family members became free men.

The five were among 39 political prisoners ordered freed today by the Philippines' new president, Corazon Aquino. She has promised to clear the country's jails of their approximately 450 detainees -- including Communists -- when former President Ferdinand Marcos fled, but it appears the military is pushing to hold on to jailed Communist leaders.

Conversations with the five, two of whom identified themselves as labor organizers, suggested that they were deeply committed leftist activists who value freedom mainly because it will let them resume their organizing.

According to human rights lawyers, how Aquino handles this issue will be a key factor in determining her ability to assert authority over the military. Marcos often had maintained that the people he jailed were secret Communists and classified them as national security cases to be handled by the military.

Among the most prominent Communists still in jail is Jose Maria Sison, a founder and first chairman of the outlawed Communist Party of the Philippines, who has been held since Nov. 10, 1977.

Many of the people Marcos jailed will be grateful to Aquino for getting them out, but not enamored of the conservative brand of politics that she brings to office.

"We're not sure yet whether it is really a victory of the people," said Romeo Castillo of Aquino's ouster of Marcos. Castillo, 32, was jailed 20 months ago on subversion charges. "It's too early to judge . . . . The members of the Cabinet are the same old faces. I couldn't find any faces there from the militant workers, from the students, from the peasants."

The experience of prison clearly has hardened the men. Cesar Bristol, 30, another labor organizer, said he had been tortured with beatings, electric shocks and threat of execution during the two-day interrogation that followed his arrest in July 1984.

After that, life became routine. As political prisoners, he and the others had privileges in prison denied ordinary criminals. In their segregated camp inside the Bicutan Detention Center on the outskirts of the city, they had private rooms, television and newspapers. They had basketball and table tennis facilities and could receive visits from relatives.

Word that they were leaving came at 8:30 this morning. Tonight, they remained unsure of their legal status, although officials said orders issued today do not clear them of charges. That will be done later in a general amnesty, they say.

Following a 30-minute ride tonight they pulled up to the office of the Task Force Detainees of the Philippines, a group working to free political prisoners that the Marcos government accused of procommunist leanings. About 20 persons were waiting and hugged and kissed them warmly.

"I do not see barbed wire, high walls, unfriendly guards," said Castillo as he stood in the lobby. "It's a new atmosphere."

Later the group, which included several nuns, sat down to a Filipino supper with mangoes and watermelon at the end. Castillo got up to make a brief speech.

"I'm happy tonight, but I am also sad," he said in Tagalog, one of the major Filipino languages. "There are still people in prison. Starting tomorrow, I intend to work so that the others may be released."