With the rank of colonel he participates in Sanjurjada,[1] the failed attempted coup d'état led by General José Sanjurjo, on 10 August 1932.

[2] Accepted by the amnesty granted by the radical government of Alejandro Lerroux, he rejoined the Spanish Army and was assigned to Valladolid, headquarters of the VII Organic Division [es].

Serrador actively participated in the military conspiracy that led to the Spanish coup of July 1936, being one of the organizers of the Nationalist uprising in the Province of Valladolid.

[3] When they arrived at the pass they found that it had already been occupied by a group of the MAOC militiamen from Madrid, but they managed to evict them during the Battle of Guadarrama, and on 25 July it was in their hands.

[5] While in command of the 71st Division, during the Battle of Brunete the initial Republican attack caught his unit by surprise, forcing them to give ground and suffering serious casualties.