8. NOTE: A proper manual bleeding of the hydraulic system requires that accurate communications occur between the person depressing the brake pedal and the person opening and closing the bleeder valve(s). The bleeder valve (also called a bleed valve ) should be open only when the brake pedal is being depressed. The valve must be closed when the brake pedal is released to prevent air from being drawn into the system.
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10. Figure 72–3 Typical bleeder locations. Note that the combination valve and master cylinder shown do not have bleeder valves; therefore, bleeding is accomplished by loosening the brake line at the outlet parts. (Courtesy of Allied Signal Automotive Aftermarket) Continued
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28. NOTE: To help prevent depressing the brake pedal down too far, some experts recommend placing a 2 x 4 in. board under the brake pedal. This helps prevent the seals inside the master cylinder from traveling over unused sections inside the bore that may be corroded or rusty.
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40. Figure 72–11 Metering valve override tool on a General Motors Vehicle. Push the end of the tool toward the valve body until it depresses the valve plunger, then tighten the mounting bolt to hold the tool in place. Continued
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42. Figure 72–12 Pull-out-type metering valves being held out using a special override tool. Continued