Gm Global Technolgoy Operations, Inc.

Timothy M Welch

David L Brademeyer

Donald M Flory

Craig A Osterday

Douglas L Osterfeld

Michael P Trego

Thomas R Baumaster

A method of adjusting the length of a vehicle brake booster output rod and assembling the same into the brake booster is provided, the output rod being a thermoplastic or thermoset material that is generally cylindrical in shape with a central longitudinal bore with an axial stop means, and the output rod having an insertable button having a head with an attached stem, the booster having a housing with a central opening surrounding the output rod with a surrounding first formed surface for mounting a master cylinder, the method including piloting a cutting tool by inserting an elongated member into the bore of the output rod, orienting the cutting tool by mating a fixture locationally associated with the cutting tool on the first formed surface of the vacuum booster housing, preloading the output rod with the elongated rod by contacting means with the elongated rod to simulate a spring load of a master cylinder, cutting the output rod with the cutting tool to the correct dimension, removing the elongated member from the output rod bore, and inserting the stem of the button into the output rod with a sheet material juxtaposed between the stem and the bore of the output rod causing an interference fit retaining the button into the output rod bore.

Pneumatic booster output rod adjustment method

Various buoyant valve arrangements are utilized to prevent quick take-up pressure from entering the master cylinder reservoir chamber until the quick take-up pressure reaches the desired value. A resiliently biased check valve is provided which opens at a predetermined quick take-up pressure to limit the amount of quick take-up pressure generated and then vents excess brake fluid from the quick take-up chamber into the reservoir chamber. The check valve may be resiliently biased by a spring or by elastic tension in an O-ring valve member.

Quick take-up master cylinder valve arrangement

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Dayton, OH, United States of America

Timothy M Welch