1. Remove the vacuum hose..
2. Verify that air can be blown from the power brake unit side of the vacuum hose towards the vacuum pump side, and that air cannot be blown in the opposite direction.

If there is any malfunction of the inner check valve, replace it together with the vacuum hose as a single unit.
Vacuum Hose Removal/Installation
Vacuum Pump InspectionOil Control Valve (OCV)
Purpose, Function
The OCV switches the oil passage to the hydraulic variable valve timing actuator
to control the opening/closing period of the exhaust valve.
Construction
The OCV is installed to the exhaust camshaft cap (No.1).
The OCV consists of a spool valve wh ...
Clutch Fluid Inspection [C66 M R]
NOTE:
A common reserve tank is used for the clutch system and brake system.
1. Verify that the clutch fluid is between the MIN mark and the MAX mark.
Verify that there is no clutch fluid leakage then add clutch fluid to the
level between the MIN mark and the MAX mark..
...
Front Stabilizer Removal/Installation
CAUTION:
Performing the following procedures without first removing the front ABS
wheel-speed sensor may possibly cause an open circuit in the wiring harness
if it is pulled by mistake. Before performing the following procedures, disconnect
the front ABS wheel-speed sensor wiring ...