What does the Vacuum Reservoir do on the 1.8t vrs ? and can it fail ?

I thought only diesels had a vacuum reservoir (large ball thing), which was used when the car was at idle, as the vacuum pump might not generate enough vacuum. Primarily it is there to supply a vacuum to the brake servo.

If similar to the diesel, then it could fail - it could get a hole in it, or the connecting pipework could leak, although I believe failure is pretty uncommon.

If ur talking bout the little one that sits above the no 4 coil pack it's there so the ecu can operate vacuumed components eg dump valve at times when their is no vacuum inside the manifold

Throw it in the bin

Edited 22 January, 201214 yr by steven carson

Yep the two things its used for are 1) opening the diverter valve via the N249 if for some reason its overboosting and it needs to vent the boost, and 2) opening the secondary air combi valve so air can be pumped into the exhaust manifold on a cold start