Assistant D.C. Police Chief Tilmon B. O'Bryant, passed over once for chief and twice for the department's number two position, will retire on March 1, and is seeking a tax-free annual pension of $32,840.50 based on his contention of full disability.

O'Bryant, 58, will go before the D.C. Police and Fireman's Retirement and Relief Board tomorrow to request full disability retirement benefits because of high blood pressure and hypertension. He has served on the force for 30 years.

O'Bryant would receive an annual pension of 70 per cent of his annual salary of $46,915, if the board approves his request.

O'Bryant was promoted to assistant chief -- one of four on the force -- on Feb. 16, 1973. At that time, he was the highest ranking black official in the department.

On Dec. 14, 1974, Mayor Walter E. Washington appointed Maurice J. Cullinane chief of police, choosing him over O'Bryant. At the same time, Washington promoted Burtell M. Jefferson, then a deputy chief, to assistant chief in command of field operations, moving him ahead of O'Bryant, who is commander of administrative services.

Jefferson the heir-apparent when Cullinane retired on disability in December, was named chief. Jefferson then passed over O'Bryant and named Deputy Chief Bernard D. Crooke as his field operations commander.

"I've been receiving treatment for problems with may blood pressure for a number of years now" O'Bryant said yesterday. "I've also started to have some trouble with my heart and I'm told by the doctor that I've been flirting with a stroke."

Dr. Robert Dyer, chairman of the police and fine board of surgeons, said yesterday that he had been treating O'Bryant for hypertension. He would not comment on how serious the problem was, saying only, "Hypertension is a serious disease."

Dyer said he had signed a letter to the board, "recommending that they consider his (O'Bryant's) request for retirement on disability. I also listed a diagnosis of his medical problems in the letter."

It is believed that the letter noted that O'Bryant was suffering from high blood pressure, headaches and osteoarthritis (stiffness of the joints) in addition to hypertension.

O'Bryant said yesterday that his blood pressure problems began "long before" his promotion disappointments. "They didn't start the problem, but I guess you could say they contributed to the problem," he said.

"Disappointment is a way of life, it's part of life," he added. "Right now I'm just planning on going away for a while and getting my blood pressure fixed." He said the problem "was not that serious yet" when he passed his promotion physical in 1973.

O'Bryant joined the force in May, 1947. He was promoted to detective in 1957, detective lieutenant in 1962 and detective captain in 1966.

In July 1969 he was named deputy chief in command of the patrol division. While a deputy chief, he was placed in charge of personnel and training and named equal opportunity officer in 1970 before becoming an assistant chief in 1973.

During the 1960s O'Bryant and Jefferson, close friends at the time, were leaders in training black police officers and were considered instrumental in the rise in the number of black police officials during the 1970s.

The friendship between O'Bryant and Jefferson reportedly cooled after Jefferson was promoted over O'Bryant. That was considered a major reason for Jefferson naming Crooke as his number two man.

"I really don't want to make any comment on anything that's gone on," O'Bryant said yesterday. "I just don't feel good."

O'Bryant currently is officially on sick leave.

Jefferson was out of town yesterday and could not be reached for comment.

O'Bryant currently stands fifth in the department in years of service. John M. Powell, chief of the U.S. Capitol Police, is first with 37 years.