Checking the bypass valve (B235R, B205L/R)
- Disconnect the vacuum hose from the bypass valve.
- Connect 30 14 883 Pressure/vacuum pump and create a negative pressure in the valve.
- Make sure the diaphragm is undamaged. If it is, it will not hold the vacuum.
- Repeat steps 2 and 3, this time creating positive pressure.
- Disconnect the pump.
- Connect the vacuum hose.