House leaders yesterday crafted a fragile deal designed to keep liberals from torpedoing the compromise Defense Department procurement bill.

In an effort to assuage liberals unhappy with what they see as a bloated Pentagon budget, the agreement relies on the appropriations process, which is separate from the procurement bill, to bring the Defense Department budget down to the $292 billion originally approved by the House.

As the appropriation bill works its way through Congress, under the agreement worked out yesterday, any House member may call for a vote of the full House if the total exceeds $292 billion -- even if the higher amount was recommended under a compromise between the House and Senate.

These legislative gymnastics are intended to avoid a repetition of the current controversy in which the Senate approved a much higher figure than the House -- $302 billion -- which was subsequently adopted by a House-Senate conference in August.

House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) and Rep. Les Aspin (D-Wis.), chairman of the Armed Services Committee, do not want the pending conference compromise to be amended because the Senate leadership has notified O'Neill that such tinkering will scuttle the procurement measure. The House Democrats also feared that a rejection of the compromise could establish a precedent for scuttling future conferences on defense measures.

Yesterday's agreement also would restore some military procurement reforms which had been deleted in the August conference.

Under House rules, it is out of order to add legislative requirements to an appropriations bill. But O'Neill and Aspin plan to enlist the Rules Committee in their effort to save the pending conference report, according to congressional sources.

The Rules Committee writes the procedures by which legislation is debated on the House floor. Under the compromise, the House would operate under a rule allowing challenges to the total in the defense appropriations bill, even if it was agreed upon in conference.

Rep. William V. Chappell Jr. (D-Fla.), who is the senior Democrat on the House Appropriations defense subcommittee after the seriously ill chairman, Rep. Joseph P. Addabbo (D-N.Y.), said last night that he sees no reason the Pentagon budget could not be cut from the $302 billion in the conference report to $290 billion.

Chappell added that he has not started hammering out the fiscal 1986 military appropriations bill, which is a separate process. "I am awaiting instructions from my chairman," Chappell said in reference to the Addabbo.

Addabbo is in the Army's Walter Reed Medical Center recuperating from surgery related to a kidney ailment. His office has said he will not return to work for at least six weeks, while some of Addabbo's friends predict his absence could be even longer.

O'Neill, in one of a series of meetings yesterday, huddled with conservatives who would prefer to have a straight yes-or-no vote on the conference report.

But there was disagreement, sources said, over whether the House still had enough votes to adopt the conference bill at the Senate figure of $302 billion. Rather than risk defeat, the conservatives are being urged to approve the compromise package.

The complicated arrangements on the procurement bill are scheduled to be the focus of the House Democratic Caucus today.