Form 801680
Page Number - 5
static Pressure test (engine off)
For diagnosing:
Cooling system leaks
set-up & Procedure:
1. Ensure the cooling system is cool and not pressurized.
Carefully remove the radiator or coolant bottle pressure cap
(Fig. 1).
2. Check to see that the radiator or coolant bottle is filled to
the proper level, and check hoses for visual damage or
leaks. Fill and repair as necessary prior to testing.
3. Apply water or coolant to the rubber gasket of cooling
system test adapter, and install it in place of the
pressure cap (Fig. 2).
4. Secure one end of the clear hose to the pressure pump
using the compression nut (Fig. 3).
5. Secure the second end of the hose to the cooling system
test adapter using the compression nut (Fig. 4).
6. Note the operating pressure of the cooling system
indicated on the cap or in the vehicle repair manual.
7. Operate the pressure pump until the needle on the
pressure gauge moves to the high end of the colored band
indicating the appropriate pressure range of the cap (see
Chart A).
caUtion: Do not pressurize the cooling system beyond
the appropriate color of band for the system being tested.
8. Monitor the gauge for at least two minutes. If the pressure
reading drops, a leak is present.
9. With the system still pressurized, perform a visual
inspection of the entire cooling system. Check hoses
and connections for seepage, which would indicate a leak.
Return to the gauge and check the reading once more.
10. Most leaks are external, and visible seepage occurs.
However, a drop in pressure with no visible leakage can
indicate a blown head gasket or cracked block, where fluid
leaks into the combustion chamber. Visually inspect oil
and transmission fluid for signs of coolant. Proceed to the
Dynamic Pressure Test for better methods of diagnosing
internal leaks.
11. When testing is complete, release the pressure in the
system by pressing the pressure relief valve located on the
pump hose near the quick-connect couple.
12. Repair leaks if necessary, and retest.
13. Disconnect components, clean and store them properly.
14. Refill the radiator or coolant bottle to the proper level, and
replace the cap.
Fig. 1
Fig. 2
Fig. 3
Fig. 4
chart a:
cooling system cap Pressure test ranges
Rated
Pressure (PSI)
Pressure Range
(PSI)
Arrow/Band
Color
4
3 - 5
Yellow
7
6 - 8
Green
10
9 - 11
White
13 or 14
12 - 16
Blue
15 or 16
14 - 18
Yellow
18
16 - 20
Black
20
18 - 22
Green
30
28 - 30
Red
