Vacuum Dump Valve
- Vacuum dump valve should be checked whenever brake application does not release speed control. Ensure that no more than 1/8" (3.2 mm) of plunger tip is extended when brake pedal is in fully released position. Disconnect vacuum hose from dump valve to servo, at servo unit. Connect hand vacuum pump to hose and pump up a vacuum.
- If vacuum cannot be obtained, hose or dump valve leaks and should be replaced. Depress brake pedal. Vacuum should be released. If not, adjust or replace dump valve.