2. Check valve #1.
- i) Apply voltage from the battery to the terminals of valve No.1 and make sure that air passes between the filter and the hose "E1".

- b) Disconnect the battery and make sure that air passes between hoses "E1" and "G".
3. Check valve #2.
- a) Apply voltage from the battery to the terminals of valve No.2 and make sure that air passes between hoses "F" and "E2".

- b) Disconnect the battery and make sure that air passes between the filter and the "E2" hose.
