Vacuum Pumps & Parts

A vacuum pump is a necessary component on a diesel engine vehicle with vacuum operated components. These components typically include the power brake booster and the actuators in the HVAC (Heating, Ventilation & Air Conditioning) system. The vacuum pump can be of the reciprocating diaphragm or rotary vane design, and driven directly by an engine component like the camshaft, or belt driven. Vacuum operated systems use the plentiful manifold vacuum available with throttled internal combustion engines like gasoline 4-cycle engines.

Manifold vacuum is created by piston movement on the intake stroke and restriction of air flow through the throttle opening. Vacuum is highest when the throttle is nearly closed such as at idle or at low speeds, and drops to zero when the throttle is opened during wide open acceleration. However diesel engines don't have throttle valves and don't produce vacuum; the power output is controlled by varying the amount of fuel injected into the cylinders.

The power brake booster contains a diaphragm that separates the two halves of the booster housing. When the brakes are not applied the diaphragm remains in a fixed position because there is vacuum on each side. When the brakes are applied, atmospheric pressure fills the chamber on the firewall side of the diaphragm, creating a pressure differential that provides the power assist. Many HVAC systems use vacuum motors to control temperature and air flow.

The short duration camshafts that are in most stock street engines are fine for the low RPM operation typical of cruising and commuting, and they allow the engine to develop plenty of vacuum for the power brake booster and other vacuum operated components like the vacuum door motors in many heating & A/C systems. But, if in your quest for horsepower, you install a high lift, long duration cam with a lot of overlap, you can end up with very little engine vacuum, a hard brake pedal and poor stopping. Our Performance Brake Booster Vacuum Pumps & Reservoirs are the low vacuum solution.