1942 - 1947 Chevrolet Shop Manual



	*5-10*



	Fig. 22—Main Cylinder Parts Layout

	Check the clearance between the edge of the primary cup and the center of the compensating port, Fig. 25. In order to check this clearance accurately the main cylinder must be partially assembled as follows:	4. After this clearance has been checked, the main cylinder must be again completely disassembled and reassembled according to the following directions.


	Fig. 23-Valve Sect Washer Assembly 1. Install pedal stop and push rod assembly and lock in place with snap ring. 2. Assemble secondary cup on piston and install assembly in housing. Place the primary cup in the housing, with the flat side of the cup against the piston. 3. Push the piston and cup against the pedal stop and check the clearance between the edge of the primary cup and the center of the compensating port. This clearance should be a minimum of 35 thousandths of an inch. This check is made easiest by using a wire inserted through the reservoir of the housing and extending into the piston chamber, Fig. 25. If the clearance is less than 35 thousandths of an inch, the primary cup must be replaced with a new one.
		Fig. 24-Checking Main Cylinder Piston Fit Reassembly Whenever a hydraulic brake master cylinder is being overhauled for any purpose, care must be taken to reassemble the valves and seats correctly. Improper assembly of the check valve seat rubber washer will result in its distortion. When the check valve seat is distorted, there will be no check valve seal and there will be a loss of brake pedal travel and the pedal must be depressed or pumped one or more times before actual car braking occurs. In order to minimize the chances of distorting the check valve seat the following method of assembly is recommended: