Washington service station owner Bill Brooks was put in a bit of a bind yesterday.

Mayor Marion Barry telephoned and asked Brooks to join him at a press conference to announce the official end to the District's ill-fated 6 percent gasoline tax.

In some respects, Brooks, who owns a tiny Northwest Washington Gulf station, could be considered the last person Barry would call. Just a few days earlier Brooks had been quoted in The Wasington Post railing against the gas tax in general and its originator, Barry, in particular.

He said then that Barry was a no-good, one-term mayor who was out of touch with Washington's working-class black community. Brooks pledged himself to work to defeat Barry in the next election.

Brooks, a barrel-chested and street-wise native Washingtonian, found a way out of his little dilemma, however. He sent Bill Brooks, the gasoline station owner to pose for pictures and answer questions with the mayor, while Bill Brooks, the private citizen and Barry-hater, stayed home. Well, almost . . . .

"You see, there are two Bill Brooks," Brooks told a reporter later. "As a business, I thank the mayor for removing the sales tax. But my ideas and policies haven't changed as far as a citizen. As Bill Brooks, the citizen, I feel there are a lot of things this city needs . . . I still think he's a one-term mayor."

When Brooks arrived at the press conference at Jack Waddy's Exxon station on North Capitol Street and Riggs Road in Northeast Washington he was greeted with a hug and a handshake from a smiling Barry, as if the two were long-lost friends. Bill Brooks, the gas station owner hugged the mayor in return and smiled -- through his teeth.

"He really put me in a bad spot in front of all the television cameras," Brooks said. Brooks said Barry was "trying to give the impression that we were real budies, but Bill Brooks the citizen just feels the same way. He is not a good mayor and I will not support him."

If the mayor couldn't convert Bill Brooks the citizen, he at least used Bill Brooks the service station owner to play a carefully choreographed scene for all it was worth. Barry posed in front of a row of microphones with Brooks, Waddy and Vid Rasheed, director of the Greater Washington Area and Maryland Service Station Association.

"One thing we wanted to do today," Barry said, "Was indicate that we had everybody together around gasoline and what we're going to do about the gasoline tax."

Rasheed said: "Speaking for all the service station dealers in D.C., I think we're very happy to forget this episode of the 6 percent sales tax and I think we're all thinking very positively right now."

It was Brooks's turn to speak, next, and he urged District of Columbia motorists to return to their city service stations to buy gasoline, once the tax is officially lifted on Monday.

The repeal of the tax is expected to reduce gasoline costs from 8 to 10 cents a gallon. The tax was imposed last August as part of Barry's package of new and increased taxes designed to raise badly-needed revenue for the city and to balance the fiscal year 1980 budget.

But the gas tax has been a failure, Barry conceded last week, since it drove numerous District residents into neighboring Maryland to buy their gas. The tax also was a nightmare to collect, as well as a political liability for the city's politicians.

To symbolize the repeal of the tax, Barry rolled back the price of two of the pumps at the Exxon station, and then filled up his official car with the lower-priced gasoline. Before getting into his car, Barry was overheard telling Rasheed, "This will be very helpful."

But Brooks was undeterred by the show. He steadfastly stood by his published comments.

"I only had one person call who was an adversary," he said of the response to the newspaper article. "The rest, oh, about 20 or 30, well, they all offered to help me get Barry. They all said they feel the same way I did, and they were glad someone finally had the guts to say something."