Check Valve Operation Check

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Remove the check valve (Refer to REMOVAL AND INSTALLATION ).
CAUTION: Replace the check valve when it is faulty.

Using a vacuum pump, check operation of the check valve.

VACUUM PUMP CONNECTION

Vacuum pump connection	Normal condition
When connected to the booster side (1)	Vacuum is generated and maintained.
When connected to the engine side (2)	No vacuum is generated.

Fig 1: Checking Operation Of Check Valve Using Vacuum Pump

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.