Porsche 991 Preventative Maintenance


991 Brake Vacuum Pump

Q. What does the brake vacuum pump do?

A. The pump provides power assistance for the braking system.

Q. What are the symptoms for the pump failing?

A. There will be a ticking/mechanical noise from the pump area. We would recommend visiting your service centre for a professional opinion.

Q. What will happened to my car if the pump fails?

A. Loss of vacuum generated by the pump, debris deposited in engine and potential catastrophic engine failure.

Q. How can I prevent the pump failing?

A. The best course of action is to personally make regular noise checks on the component or ideally have the unit examined/replaced by a trained technician during routine servicing.

Fig 1.

Good working order

The above image represents a used Brake Vacuum Pump in good working condition.

Fig 2.

Damaged unit

The above image represents a used Brake Vacuum Pump that has seized resulting in material stress, bending to the metal arm and deposit of debris in the engine.

Fig 3.

wear to casing

The above image represents scoring to the pump housing. This will be caused when the metal arm seizes and bends (shown in Fig 2.). Heat from the friction of the two components causes discolouration of the metal (black marking to the right hand side of the casing).