Piston puller

Claim 1

Apparatus for use in removing and reinstalling pistons in disc brake assemblies of the type including a caliper housing providing a bore in which a piston is reciprocably disposed, the bore being open at one end and closed at its opposite end, and an outboard shoe support bracket spaced axially apart from the open end and having axially outer and inner sides and an opening therethrough generally aligned with the bore, the piston being a hollow cylindrical piston with a closed end adjacent the closed end of the bore and an open end adjacent the open end of the bore, said apparatus comprising a threaded shaft having a distal end, a proximal end and an intermediate portion, said shaft being proportioned and designed to extend axially through the opening in the support bracket with its said distal end received in the hollow of the piston, first abutment means affixed to the distal end and proportioned and designed to be received in the hollow, second abutment means threadedly engaged on said shaft for movement toward and away from said first abutment means, a rubber-like grommet disposed on said shaft between said abutment means to be at least partially received in the hollow, said grommet having a free outer diameter less than the internal diameter of the hollow, said grommet being radially expansible to a diameter greater than the internal diameter when axially compressed between said first and second abutment means frictionally to engage and grip the piston, and third abutment means threadedly engaged on said intermediate portion for movement relative thereto, said third abutment means being engageable with the axially outer side of the support bracket to pull the piston outwardly and with the axially inner side of the bracket to push the piston inwardly.