Checking the Diaphragm Unit

Checking the diaphragm unit

If basic boost pressure cannot be adjusted, check the following:




1 Check that the diaphragm unit's pushrod can move freely without binding.

2 Check the diaphragm and spring by connecting a tester to the diaphragm unit's connection. Pump up the pressure and check that the pushrod is pushed out and displays no tendency to bind.

3 Release the pressure and check that spring force causes the pushrod to reenter the diaphragm unit.

4 Change the diaphragm unit if it is defective.