Abstract: Disclosed is an improved piston construction for use in a braking system. The piston construction employs an insulator at its inner end and a conical aperture at it outer end. Both of these promote increased heat isolation during braking operations. The piston of the present invention also employs an o-ring which is secured within a cylindrical recess. The o-ring ensures a fluid tight seal between the piston and the piston housing. Through the use of the o-ring, air is prevented from entering the brake lines.