When Montgomery County police officers squeeze into their union clubhouse in Gaithersburg tonight, they will consider again whether the most practical way to address their grievances is to vote no confidence in Police Chief Donald E. Brooks.

The union, Fraternal Order of Police Lodge 35, delayed a no-confidence vote July 10 after County Executive Sidney Kramer agreed to purchase 66 new take-home police cruisers for $1.3 million and initiate "good-faith" discussions on other union concerns.

The real question for the union, according to its leaders, is whether the county government and Brooks have made enough progress on other fronts in the past five weeks. A related question is whether the union gains more leverage by postponing the vote than it does by taking it, the leaders said.

"We have to weigh these heartfelt feelings about the department, but at the same time get something intelligent done," said Officer R.J. Mills, a 15-year veteran of the force and an officer in the Germantown district station.

Mills said union leaders persuaded members to postpone the vote in July for political expediency. "Police officers are everyday working people who don't normally deal with politics," Mills said. "But we have to understand that this is a political ballgame and see what we can get out of this."

The county police force has 850 sworn officers, and about 800 of them are members of the union. However, officers below the rank of sergeant, who total about 250, are the only ones the union represents in negotiations. At tonight's meeting, the union also may announce its endorsement in the increasingly bitter Democratic primary for county executive between Kramer, who was spurned in 1986 by the police union, and challenger Neal Potter, a two-decade County Council member.

Discontent is still high among the rank and file, according to officers interviewed. "There is still a feeling of no confidence in the situation," said Bethesda Officer Juan Price. Officers are unhappy about promotions, minority recruitment and a general perception of poor leadership by Brooks, he said. "We're in a holding pattern," Price said, "waiting to see what changes come in the next couple of months."

The union's top priority -- the new police cruisers -- appears to be headed for final approval by the County Council Sept. 18. A council committee this month approved Kramer's budget request for the cruisers.

By month's end, about 2,000 mobile and portable police radios are scheduled to be inspected for maintenance and minor repairs in response to complaints about frequent breakdowns in the communications system. A consultant's study recently recommended a $10 million overhaul of the system by 1996.

There has been less progress on other union grievances. For example, questions remain on such policy issues as how disabled officers can be utilized; whether officers can purchase 9mm semiautomatic weapons for their own use and whether the department should change to the 9mm standard; and how to resolve scheduling conflicts for officers who have court appearances. Proposals to relax restrictions on second jobs for officers are being reviewed by the county's Ethics Commission.

Union leaders said they realize they must deliver results at tonight's meeting to avert a no-confidence vote against Brooks and themselves. "We want to have concrete, definite answers," said union President Walter Bader. "I'm under the gun to do the best to follow through and get some things done."

For Brooks, appointed chief two years ago by Kramer, the reprieve has provided a chance to improve relations with the union and bolster his public image. "I'm pretty well satisfied that things are better," Brooks said Tuesday.

Brooks, a 40-year veteran who some officers criticized as being out of touch, said last week that "a concerted effort has been made on every union issue."

Officers on the street are more cautious. "Officers are afraid now that all this is pre-election rhetoric," Mills said. "After Nov. 7, this stuff could all go by the wayside if we don't push now."

Many officers said the department's problems stem from "growing pains" of a suburban police force.

"The problem is not just Brooks," Price said. "We're not keeping up with progressive policing strategies in weapons, cars and computers . . . . The fault is the County Council and the whole political system."