The brake booster check valve could be defective. This is something easily overlooked. To check, remove the valve from the booster and disconnect from the hose supplying vacuum. Blow into the valve on the hose booster side. If air travels through and comes out the hose side, then you have a bad check valve.
Those born on the Virgo-Libra cusp enjoy beauty and all things sensual. They may find themselves drawn to the arts, attractive people, and precious objects or wish to make themselves and their surroundings more pleasing to the eye.
Virgo is an Earth Sign, and is the most practical sign of the Mutable Quadrature. Their reasonable nature and practicality can descend to criticism, but that's because of the protective nature of the Earth Element, which drives them to try and help others.