Page Number - 4 Form 801625
Applications & Basics of Testing
The MV4560 Cooling System Test Kit is designed
to diagnose and pinpoint the presence of leaks in
an automotive cooling system. It contains equip-
ment to manually pressurize and monitor the pres-
sure in a cooling system. Leaks are indicated by a
drop in pressure over a few seconds or minutes.
The location of an external leak(s) is pinpointed
by the visible seepage of fluid resulting from the
pressure. Internal leaks, which may not be visible,
typically indicate a blown head gasket or damaged
block or head, and can be diagnosed by monitor-
ing the pressure during a quick “engine on” test.
The MV4560 can also be used to test cooling
system pressure caps, which utilize a relief valve
for protection against over-pressurization. A
malfunctioning cap can cause over- or under-
pressurization of the cooling system, leading to
overheating and/or severe engine damage.
Precautions
This equipment is designed for servicing a
variety of vehicles in a safe, convenient manner.
However, differences in cooling systems may
make it impossible to perform some of the tests
indicated in these instructions on every vehicle.
The procedures documented in this manual are to
serve as guidelines for the use of this equipment.
In addition to these guidelines, always follow the
manufacturer’s recommended procedures when
servicing each unique vehicle. Do not attempt to
force a test on a cooling system for which this
equipment is not designed to perform.
Performing cooling system tests using the MV4560
is simple and straightforward if you follow the
instructions. However, always keep in mind that you
are working with a system that may be full of cold
or hot fluid that is under pressure and just waiting to
be expelled.
If you are testing an engine that is hot and/or pres-
surized, always stop to think before pressing the
relief lever, removing a cap, or disconnecting a hose
or other component.
Always read carefully and understand instructions
prior to using this equipment.
Always wear eye protection when removing radia-
tor or coolant bottle cap, or when performing any
cooling system test.
Never remove the radiator or coolant bottle cap,
or attempt to pressurize the cooling system of a
vehicle that is overheated.
Always allow system to cool prior to attempting to
perform any cooling system related test proce-
dure.
Basics of Cooling System Testing
When deciding where to connect to the cooling
system, first look for the radiator and determine if
it has a fill neck and pressure cap. This is common
on about half of US manufactured vehicles, and
almost all Asian manufactured vehicles, and would
be the first choice for connecting. If the radiator is
closed and inaccessible, then the connection will
be made through a coolant bottle. Some automo-
tive cooling systems utilize a coolant overflow
bottle that is not part of the sealed system. At-
tempting to test the cooling system through this
bottle will not connect you into the sealed system,
and will simply vent the test pressure to the atmo-
sphere. This type of overflow bottle is easily recog-
nized because it typically utilizes a snap-on style
cap or a threaded cap that is open to atmosphere.
No adapters are designed to fit this type of coolant
overflow bottle. A test connection should be made
through a radiator or coolant bottle with a bayonet
or threaded style of cap designed to maintain a
specific range of pressure in the cooling system.
Basics of Cooling System Cap Testing
Cooling system caps have a built-in pressure
relief valve. The valve allows pressure to build in
the cooling system, but vents the pressure when
it becomes too high. While the cooling system
has a pressure specification, it’s the responsi-
bility of the cap to maintain pressure within a
precise range of the specification.
Cooling system caps are marked with the rated
pressure of the cooling systems for which they
are designed to be used. Chart A on page 7
indicates the range of pressure the cap must
maintain in the system based on its rated pres-
sure. The cap must not leak below the low limit
of the range, and must not open below the high
limit of the range.
On the face of the pressure gauge, colored ar-
rows are used to indicate the pressure rating of
the cooling system, while colored bands indicate
the range of the corresponding cap.