Sliding caliper type disc brake

A sliding caliper type disc brake comprising, a brake disc which is capable of rotation, a torque member which is fixed to the frame of the vehicle or another similar part of the vehicle and which has circumferentially spaced torque receiving parts on both sides of the disc respectively, friction pads which are coupled with said torque receiving parts and guided so as to be mutually slidable on said torque receiving parts to permit frictional braking engagement of said pads to opposite sides of said disc, and a caliper member which straddles over the outer circumference of said disc and is operable to move said friction pads into braking engagement with said disc, said caliper slidably guided with respect to said torque member by a pair of pins connected to and extending from one of said members and slidably received in corresponding guide holes penetrating through the other of said members, the improvement comprising a pair of bush boots of an elastic material seated in and lining said guide holes and normally closed at one end thereof for respectively slidably receiving said pins therein and normally closing off the free ends of said pins from the exterior atmosphere, said bush boots having integral dust boots at the other ends thereof which freely expand and contract between said members to close off said pins from the exterior atmosphere at their ends of extending connection to said one member, a small aperture provided in the normally closed end of said bush boots to vent the interior volume of said bush boots between the free ends of said pins and the normally closed end of said bush boots directly to the exterior atmosphere and said apertures being normally closed by the elasticity of said bush boots to prevent entry therethrough of foreign matter into the interior volume of said bush boots.