The Pump - Craftsman 20930 Operator's Manual

The vacuum pump is an extremely versatile service
tool that can be used to test a variety of automotive
systems and perform a number of useful tasks.
Though the pump has obvious uses for testing
various vacuum motors, control valves and vacuum
sources, its applications don't end there. Almost
any part or system that requires proper sealing,
pressure or vacuum to operate can be tested with
the vacuum pump. The pump and its accessories
also transfer fluids, help to bleed brakes and aid in
other tasks. The pump also meets diagnostic tool
requirements when such tools are specified for some
state vehicle inspection programs.
This section will describe the pump, give
specifications, tell how to use the pump and
provide some service tips to help you keep your
pump in tip-top shape.
DESCRIPTION
The hand-held vacuum pump is simple, accurate,
easy to use, and has many applications. It consists
of a pump body, moveable handle, vacuum gauge,
vacuum fitting and a safety-capped pressure fitting.
The pump is easily held in your hand, and when the
handle is squeezed, a vacuum is drawn at the
vacuum fitting. If the vacuum fitting of the pump
is connected to a closed container or system, the
gauge will show the vacuum level. If the pressure
fitting is attached to the container or system, a
pressure will be generated but will not show on the
gauge. If it is desired to read the amount of
pressure, a separate pressure gauge is required.
VACUUM RELEASE
The vacuum is released by pulling back on the
Vacuum Release Lever. This action allows air to enter
the system, thus relieving the vacuum. Vacuum will
also be released when the hose is detached from the
vacuum fitting.

THE PUMP

SAFETY CAP
The small cap on the pressure fitting is pressed on
with a friction fit. It can be removed with a twisting
pull. The cap is used to prevent any fluids (brake
fluid, gasoline, etc.), which may have accidentally
been pulled into the pump, from squirting into the
user's eyes. For this reason, the cap should always
be in place when using the pump, except when
attaching a hose to the pressure fitting. The pump
will last for many years when cared for properly.
See PROPER CARE in this section.
SPECIFICATIONS
Maximum Vacuum
@ Sea Level:
Stroke Volume:
Maximum Pressure
(Unassisted):
(Assisted):
Gauge Accuracy
(15-20 in Hg):
USING THE PUMP
The vacuum pump is simple to use. In most cases,
the pump is either attached directly to a component,
used in place of a vacuum line or connected into a
vacuum circuit with a tee connector. The pump can
be operated as a test instrument in three ways:
1) When vacuum is desired for a test, the movable
handle of the pump is simply squeezed with your
hand, as in clenching your fist. Continue strokes
until desired vacuum is indicated on the gauge.
2) The pump can be connected into a vacuum circuit
and used to measure existing amounts of vacuum,
just as any vacuum gauge would be used. When
used this way, do not pump the handle, or incorrect
readings may result.
2
Approx. 25" Hg
(85 kPa)
1 cu. in. (16cc)
15 psi (103 kPa)
30+ psi (207+ kPa)
3%-2%-3%
of full range