Checking the T-valve
WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Use hose pliers 1158957 to pinch off the vacuum hose of the brake servo.
Use a screwdriver to undo the connection to the intake manifold. Press the lock ring straight down while pulling the hose connection outward.
- Blow in the intake manifold side. If it is not possible to blow through, the valve is OK.
- Suction the intake manifold side. If it is possible to suction air through, the valve is OK.
If the results of the above are not satisfactory, replace the T-valve.