Any police officer, policeman or employee adversely affected by any action taken by the chief which he is required to report to the board under the provisions of subdivision (1) of section 84.500 shall have the right to have such action of the chief of police reviewed by the police board upon filing with the secretary of the board within ten days after the effective date of such action a written request for review by said police board. Whereupon the police board shall grant a public hearing within fifteen days after the filing of such request. The board shall have the power to inquire into all the facts and circumstances pertaining to such action and may compel the attendance of witnesses by subpoena at the request of either the police officer, policeman or employee involved, the chief of police or any member of the board. The board shall have the power upon such hearing to affirm, modify or reverse such action of the chief and may make such other orders as the board may deem necessary. The board shall report all decisions in writing to the chief of police and to the officer or employee involved. Each decision of the police board in such cases shall be final and not subject to review by any court.