When state Superintendent of Schools David Hornbeck made one of his regular visits to Montgomery County earlier this year, school officials decided to take him on a tour of Montgomery Blair High School in Silver Spring.

The school's aging brick buildings house one of the county's highest minority enrollments -- 54 percent of its 1,630 students are black, Asian or Hispanic. School officials hoped the tour would demonstrate to Hornbeck that Montgomery is no longer a predominantly white, wealthy suburb, and that it needs state funds as much as any other locality.

Hornbeck visited a crowded business-education class, greeted teachers in sparsely furnished lounges and met with a group of students with last names such as Argueta, Kao, Dajani and Pardo. Yet that evening at a public forum, he warned Montgomery residents against "me-ism" and said their county had a obligation to extend a fiscal helping hand to other counties under the state formula for supporting the schools.

If Montgomery school officials are quick to advertise their growing minority enrollments, they seem less eager to acknowledge charges that they have failed to address the problems that arrived with the minority students. Some parents say Montgomery's desegregation efforts are a failure. The Department of Education has notified the school system it may lose $625,000 in federal funds because it has allowed schools to become racially isolated.

The student body is more than 50 percent minority in 14 schools, all of which are in Takoma Park or Silver Spring.If school officials cannot disaprove the Department of Education's charges that they have allowed segregation to take place through inaction, they will lose Emergency School Aid Act Funds that have paid for staffing to help the system assimilate the new minority children.

Officials involved in integration efforts say they have tried to make it work, but that Montgomery County's rapid demographic changes in the past 10 years have made the task "like shooting at a moving target," as one advisory committee member put it.

In the last decade, the numbers of blacks, Asians and Hispanics increased throughout the county, and the most dramatic changes were in the Wheaton electoral district, which includes Takoma Park and Silver Spring. There, the number of blacks more than tripled, from 9,020 in 1970 to 27,459 in the 1980 census. In the same period, the overall population declined by 19,517 persons.

Montgomery's black population more than doubled countywide, rising to 8.8 percent of the citizenry. More than half of all the county's black residents live in the Wheaton area. Asians and other minorities numbered 7,324 in 1970 census and 32,812 in 1980; many of the newcomers in these categories live in Rockville and Wheaton.

The school system has tried to cope with the problems brought on by the demographic shifts by offering special English-language classes and bilingual programs, and assigning teachers assistants to classes with large numbers of minority students.

A desegregation plan, adopted in 1975, reorganized seven of the elementary schools in order to reduce the nearly 100 percent minority enrollment of Rosemary Hills Elementary School.In two years, the plan brought the minority enrollment down to 48 percent. In every year since then, however, the minority factor has increased, so that now Rosemary Hills has about 55.5 percent minority students.

School officials say the minority population has grown beyond their expectations and there is a limit to what they can do when so many black, Asian and Hispanic families move into the Takoma Park-Silver Spring area to take advantage of the lower cost of housing there. The problem, they say, must be shared with the county government.

"Social services came in with special programs for our area, helping with jobs and housing. But what they never thought about was that in providing services only in our area, they were going to impact heavily on schools," said Barbara Gordon, who once chaired a committee that worked on the desegregation plan.

The Department of Education charges, however, that the county has allowed transfers that have aggravated racial imbalance in the enrollments of six schools. In a letter to schools Superintendent Edward Andrews, Shirley McCune, a deputy assistant secretary, said the county also has assigned minority teachers to schools with high minority enrollments in such a way as to "identify certain schools as intended for students of a particular race."

School officials went before the Department of Education yesterday to answer the charges.

They say the transfers, in fact, slowed what otherwise might have been massive flight of white students. The school system has set up special programs in some of the Takoma Park and east Silver Spring schools -- such as the French immersion program at Four Corners Elementary and the science program at Piney Branch -- to encourage transfers among the seven schools in the program "cluster area."

In some of those schools, minorities comprise less that 30 percent of the enrollment while in others, the proportion of minorities is as high as 70 percent. The integation goal, 40 percent minorities in each school, was not reached partly because some programs proved more attractive than others, but also because the cluster area did not include enough white students, it was said.

"It has not succeeded in desegregating schools although kids were shifted around," said Gordon. "We didn't realize that the demographic were not the same, and that we were not shooting at 40 percent, but at a moving target," she said. "We had a large increase of Indochinese families and a white population that was growing older -- people like me, whose kids are in college."

Yet many parents whose children attend high minority-enrollment schools say they feel the school board is not committed to desegregation and is willing to let a small pocket of schools educate a student body that is more diverse than anywhere else in the county.

"We don't think they've got the nerve to undo the cluster," said Ellen Rodin, whose children attend the Rosemary Hills and Chevy Chase elementary schools. "They will allow the likes of Rosemary Hills and Chevy Chase to die a slow and agonizing death."

Rodin was among a group of parents who filed a complaint with the Office of Civil Rights last fall, accusing the school system of allowing white students to transfer out of the Rosemary Hills school even after minority enrollment topped 50 percent, the limit set by school integration policy. The civil rights office says it has not yet completed its investigation of the complaint.

At the same time, blacks in the county have criticized what they call the lesser education their youngsters have been receiving, and they point to a 15 percent difference between blacks and whites in Maryland Functional Reading Test scores. They also complain of a disproportionately high number of blacks among students suspended from school, and the disproportionately low number of black students in the gifted and talented program.

Members of a Minority Relations Monitoring Committee attended a school board meeting last week to discuss remedies, but they walked out of the room when they learned that four members of the board -- Marion Greenblatt, Suzanne Peyser, Joseph Barse and Eleanor Zappone -- had written a letter to President Reagan and Secretary of Education Terrell Bell, protesting a federal civil-rights investigation into student suspensions in Montgomery County.

Representatives of the Office of Civil Rights have been visiting Montgomery County schools as part of a regular review of schools systems that may be violating students' rights.

"We are alarmed at the scope of this office's unchecked authority to investigate disciplinary procedures in our county schools," said the letter from the four school board members. "This investigation appears to us to be a 'fishing expedition,' or at the least an overzealous application of rules and procedures."

Board member Blair Ewing accused other members of the board of "continuing indifference and occasional hostility to the needs of schools and communities where there are substantial numbers of minority students."

Parents, too, have expressed dismay at the board's attitude.

"That's discouraging," said Gordon of the letter protesting the civil-rights investigation. "I was hoping that they are basically interested in integration, quality education and equity, and will work with the community to make sure we have the kind of education for the kids that we want. That's very discouraging."