Two Yale students who were suspended last month for participation in a dorm prank are suing the university for $25,000, charging that improper procedures were used in handling their discipline cases.

Thomas Mason and Hugh Winokur, both juniors, are two of nine students who received suspensions of up to four academic terms for dropping butiric acid, a strong smelling chemical, into a Yale dining hall, causing an estimated $6000 in damage.

Pending a hearing on their case, the two students are seeking a court injunction to permit them to return to school this semester.

Jonathan Silbert, Mason's lawyer, said yesterday when the students appeared before the Yale Executive Committee certain procedural rules, including a prohibition against self-incrimination and publication of personal and academic records without prior consent, were broken.

Of the 14 students who appeared before that committee, nine received suspensions, two were placed on probation, and three were reprimanded.

The suspended students were fined approximately $500 apiece to pay for the damages.

One of the suspended students, who asked not to be identified, said yesterday, "Everyone was absolutely shocked. The amazing thing was that they ahve never done anything so harshly before. They gave no reason except that they felt the penalties were commensurate with the different degrees of involvement."

The student added that the committee, made up of equal numbers of tenured faculty, junior faculty, and students, was under considerable pressure from all sides but that the end result was a good indication of where the power in the university lay.

Due to Yale's vacation schedule, university officials could not be reached for comment.

The damage occurred when one dorm decided to retaliate against a prank played on them by a rival dorm. Before the school's annual bladderball game, students climbed up to the dorm roof and dropped the vomit-smelling chemical through a grate into the dining hall during breakfast.

Part of the roof had to be replaced and the whole room completely deodorized.

The master of the damaged dorm asked students to come out and turn themselves in. Within two days every student involved had come forward and co-operated fully with the committee, John Harris, news editor of the Yale Daily News, said yesterday.

"Even though we told the truth and did what we thought was right, this is how we were rewarded. This is our end result," one of the suspended students said yesterday