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EGR System

  1. Remove throttle valve housing, EGR crosspipe and EGR valve every 15, 000 miles. Clean calibrated hole in exhaust manifold by using a 0.20" drill bit (0.39" on automatic transmission and 1975-77 models). Flush crosspipe with trichloroethylene and blow out with compressed air.
  2. Clean inlet and outlet of EGR valve by using a rotary wire brush. Take care not to damage valve stem during cleaning. Flush out valve with trichloroethylene. Using a vacuum tester, create a vacuum to open valve. At same time, blow compressed air through valve.
  3. Check opening and closing of valve by using vacuum tester. Clean hole in intake manifold using a 0.39" (10 mm) drill and remove any deposits which may have formed inside manifold. Reinstall all components using a new gasket on EGR valve and throttle valve housing. Start engine and make sure that system does not leak.
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