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 InspectionRear Stabilizer Removal/Installation [Awd]
WARNING:
Verify that the rear crossmember is securely supported by a jack. If the
rear crossmember falls off, it can cause serious injury or death, and damage
to the vehicle.
CAUTION:
Performing the following procedures without first removing the rear ABS wheel-spee ...
Synchronizer Mechanism [C66 M R]
Purpose, Function
For smooth gear changes, the synchronizer mechanism synchronizes the rotation
of the engaging area and engages gears.
Construction
Detent ball-type synchronizer key
A detent ball-type synchronizer key has been adopted for the synchronizer
mechanism ex ...
Fuses
Your vehicle's electrical system is protected by fuses.
If any lights, accessories, or controls do not work, inspect the appropriate
circuit protector. If a fuse has blown, the inside element will be melted.
If the same fuse blows again, avoid using that system and consult an Authorized
Ma ...