Equus 3660 - Hand Vacuum Pump & Brake Bleeding Kit - Manual (Page 7)

3660 5
B. VACUUM DISTRIBUTION SYSTEMS
In order to supply vacuum from the intake manifold to the various
vacuum-operated devices found on an automobile, a vacuum
distribution system is needed. Vehicle manufacturers install vacuum
ports and/or vacuum distribution blocks in the intake manifold. Most
vacuum-operated devices are connected to these vacuum ports/vacuum
distribution blocks using vacuum hoses, lines and fittings.
NOTE: Some vacuum ports are located above the throttle plates of the
throttle body and only supply vacuum when the throttle plates open.
This type of connection is called "Ported Vacuum". On some vehicles,
emission-related devices such as EGR valves or distributor vacuum
actuators are designed to operate only when the vehicle is driven under
certain conditions. Ported vacuum is used to operate these devices.
C. USING THE VACUUM PUMP
The vacuum pump consists essentially of a pump body, a moveable
handle, a spring-loaded piston rod, a vacuum gauge, a vacuum fitting
and a vacuum release system (see Figure 2).
The vacuum pump can be used in almost any application where
vacuum must be generated, or where existing vacuum within a system
must be measured. In most cases, the vacuum pump is connected
directly to the vacuum port of a component, or is connected into a
vacuum hose in the system using a tee connector. The following
paragraphs outline the basic modes of operation for the vacuum pump.
Specific uses for the vacuum pump are provided later in this manual.
GAUGE
VACUUM
PORT
VACUUM
RELIEF
VALVE
FILTER MAIN BODY
PISTON ASSEMBLY
SPRING PUMP HANDLE
Figure 2. Hand Vacuum Pump - Exploded View