A device comprising a dust seal retaining disc an upper body and dust seal which has been developed to be used in all pneumatic brake systems, which provides reliable impermeability, the device further comprising an upper body, a shaft and a return spring which enables to retract the saft wherin said dust seal has been provided to protect said shaft from environmental effects and which functions as an impermeability element, the device furthercomprising • a protrusion which prevents the return of the dust seal bottom impermeability edge, which eliminates the possibility for a leakage to occur at the side facing the upper body, wherein said protrusion is placed between the upper body and the return spring, • a single connection area, between the upper body and the dust seal retaining disc, thanks to the elastic structure of the dust seal impermeability edge, • and a return spring centering form of the dust seal retaining disc which is located between upper body and the return spring, wherein • the retaining disc is positioned between the upper body and the return spring, • the return spring is placed on the return spring centering form in order to limit the motion of the return spring at the horizontal axis, wherein • the upper impermeability edge of the dust seal provides impermeability between the shaft and the atmosphere, preferably by tightening the shaft by means of a suitable assembly and the dust seal bottom impermeability edge is compressed into the connection area that has been formed between the dust seal retaining disc and the upper body thanks to its elastic structure, wherein • the retraction of the dust seal bottom impermeability edge is prevented without any leakage and with reliable impermeability by means of the groove that has been provided at the side facing the upper body of the dust seal retaining disc. • a protrusion which prevents the return of the dust seal bottom impermeability edge, which eliminates the possibility for a leakage to occur at the side facing the upper body, wherein said protrusion is placed between the upper body and the return spring, • a single connection area, between the upper body and the dust seal retaining disc, thanks to the elastic structure of the dust seal impermeability edge, • and a return spring centering form of the dust seal retaining disc which is located between upper body and the return spring, wherein • the retaining disc is positioned between the upper body and the return spring, • the return spring is placed on the return spring centering form in order to limit the motion of the return spring at the horizontal axis, wherein • the upper impermeability edge of the dust seal provides impermeability between the shaft and the atmosphere, preferably by tightening the shaft by means of a suitable assembly and the dust seal bottom impermeability edge is compressed into the connection area that has been formed between the dust seal retaining disc and the upper body thanks to its elastic structure, wherein • the retraction of the dust seal bottom impermeability edge is prevented without any leakage and with reliable impermeability by means of the groove that has been provided at the side facing the upper body of the dust seal retaining disc.