Vacuum pump Volvo 780 B280 (-1987)

A hard brake pedal or poor servo assistance on an early 780 with the B280 engine can point to insufficient vacuum – and in that case the vacuum pump, the non-return valve and the hoses should be checked before suspecting the brake servo itself. On the V6 this is the system that feeds the servo with vacuum, and a cracked hose or a leaking non-return valve are common reasons for the vacuum to drop.