The present invention relates to a repair kit for inflatable articles such as tires, comprising a container (10) of sealing liquid, with connecting means (12) for connecting to a compressed air supply and outlet means (17) for connecting to the article to be repaired. Furthermore, the container (10) consists of an outer shell acting as a cylinder and an inner part acting as a piston (13) driven forward in the cylinder by compressed air, and forcing the sealing liquid into the article to be repaired. At a specific position the piston (13) is brought into contact with means (20) causing the compressed air to pass the piston (13) and flow into the article to be inflated. When the container (10) is empty, air is automatically pumped through the cylinder, and the air passes the piston (13) so as to end in the inflatable article.