On 1 April 1913, Kleikamp entered the Imperial German Navy as a Seekadett on. After basic training, he transferred to Marineschule Mürwik on 3 April 1914. After outbreak of World War I, he was posted as a communications officer to, where he received promotion to Leutnant zur See in 1915. From March 1918 he attended Ubootschule and later served as watch officer on until October 1918, when he became clerical officer of the 1. U-Kreuzerflottille until the end of the year.
Reichsmarine
Kleikamp remained with the navy after the collapse of monarchy in November 1918, serving in Marine-Brigade Ehrhardt. He received provisional promotion to Oberleutnant zur See on 7 January 1920, which was confirmed on 14 May 1921. On 1 October 1920, Kleikamp was posted on as communications and watch officer. On 4 December 1921 he was transferred to the pre-dreadnought battleship in the same capacity, where he served until he was given command of the on 1 October 1922. After a year as commanding officer, Kleikamp joined the faculty at the Marinenachrichtenschule on 1 October 1923. Having received promotion to Kapitänleutnant in 1925, he joined the battleship on 24 September 1926 as Rollenoffizier. When Hannover was put out of service, he transferred to, the new flagship of Marinestation Nordsee, in the same role. From 28 September 1928 Kleikamp was the officer responsible for training and education on the cruiser, before being appointed director of the Nachrichtenmittelversuchsanstalt on 11 February 1930. He served in this position until October 1932, when he was appointed naval liaison officer to the Wehrkreiskommando I in Königsberg, having been promoted to Korvettenkapitän. Following the Nazi Party takeover in January 1933, Kleikamp became 4. Admiralstabsoffizier in the Fleet Command.
Kriegsmarine
On 26 September 1935 Kleikamp was made first officer on, the ship which he would eventually command after a stint as director of the Gruppe Technisches Nachrichtenwesenin the Navy High Command. On 26 April 1939, having been promoted to Kapitän zur See a year earlier, was given command of Schleswig-Holstein, which had returned from a tour to South America a few weeks earlier. Schleswig-Holstein was to be retired and converted into a remotely controlled target ship, but preparations for the Invasion of Poland, saw the ship in a critical mission. Late in August 1939, Schleswig-Holstein was sent to Danzig on a friendship visit, in place of the cruiser Königsberg. The visit was a ruse to bring a landing force to Danzig in order to neutralize Polish fortifications in the harbour. For this purpose Schleswig-Holstein had received 60 men with five 2 cm AA guns and six machine guns. While en route, Schleswig-Holstein rendezvoused with the and other vessels, carrying the 225-men strong Marinestosstruppkompanie from Memel.
Kleikamp became a Prisoner of War on 7 May 1945 and remained in British custody until 18 April 1947. In poor health, he was unemployed until Spring 1952, when he joined Hugo Stinnes in Mülheim an der Ruhr. There he died on 13 September 1952.
