Senate Majority Leader Robert Bryd (D.W.Va.,) said today that he told Soviet leader Leonid Brezhnev in a meeting Wednesday there is an "imperative need for moderation in statments" by the Soviets as the Senate debates the new SALT II treaty.

Bryd did not say whether Soviet officials had restated earlier warnings against any alteration of the treaty. But he indicated cautiously that the Soviet attitude may be more flexible than was previously detected from the statments by Brezhnev and his Foreign Minister Andrei Gromyko.

During their Vienna summit last month, Brezhnev warned President Carter that Senate changes of the arms pact would threaten bilateral and world stability. Gromyko later asserted that it would be "impossible" to reopen talks if the Senate rejects or alters the treaty.

At a press conference at the end of his five-day visit here, Bryd said he still had not made up his mind which way to vote on the treaty. Senate Minority Leader Howard Baker has announced his opposition to the pact.

Speaking of his session with Brezhnev at the Soviet president's vacation retreat in the Crimea, Bryd asserted, "I do feel that some of the responses were satisfactory and others not so satisfactory. But even in that regard, I'm saying it may take some time before it's ultimately known what the Soviet response actually will be."

Bryd, whose support was crucial to the Carter administration's successful Senate fight for ratification of the Panama Canal treaty, is once again a key figure in the debate and vote on the strategic arms pact, which faces an uphill Senate fight.

Bryd said he and the Soviets discussed the treaty protocol, Brezhnev's personal assurance to Carter at the Vienna summit that the Soviet Union will not produce more than 30 supersonic "Backfire" bombers a year during the life of the treaty, and the question of "non-circumvention in the treaty . . . veriification of compliance, and the role of the Senate" in the treaty process.

Byrd said that he "discussed in a general way" with Brezhnev "some of the points" of the treaty that the Senate may attempt to alter. Brezhnev "lisened carefully and responded in particular instances," Bryd said. The senator refused to be more specific.

"I did not come here expecting simple answers, [or] quick answers in all respects, and many of the answers to my questions and suggestions undoubtedly will unfold in the days and weeks ahead," Bryd said. He did not elaborate on what "suggestions" he had made to the Soviets. He added at another point, "I am saying that in regard to some of the matters, time will tell with respect to the Soviet response."

"What I've heard here will be helpful as I weight all of the facts in reaching my decision," he said.

Bryd said that the 72-year-old Brezhnev was "very attentive, very alert, and animated from time to time" during their talk. "He listened very carefully and responded to the issues that I raised," the senator said. Brezhnev went to the Crimea immediately after returning from Vienna. Bryd described the atmosphere as "congenial, frank, useful and informative."

Asked if he had been "reassured" by his talk with Brezhnev, Bryd responded, "Not in every detail. In some, on the whole, yes. I think the discussion was very useful, very helpful to me, and I believe [it was] a way of contributing to better understanding by the Soviets of those matters of concern to my collegues as we develop this internal debate."

Bryd said that he "didn't presume to think the Soviets did not understand the role of the Senate on the constitutional process we adhere to. But I do believe my conversations have added to their understanding and I feel that this in itself will be a contribution to the debate."

The senator met today with Gromyko for more than two hours. Gromyko was accompanied by Gen. Sergei Akhromeyev, a deputy chief of the Soviet General Staff who is well-versed in SALT matters. Bryd cut off the press conference without describing this meeting. The senator rode out ot the airport with Yuri Zhukov, a veteran Pravda columnist, taking an interview on the way.