Form 801680
Page Number - 7
9. When testing is complete and the engine is cool, release
any remaining pressure in the system by pressing the
pressure relief lever located on pump.
10. Repair leaks if necessary, and retest.
11. Disconnect components, clean and store them properly.
12. Refill the radiator or coolant bottle to the proper level, and
replace the cap.
cap Pressure test
For diagnosing:
Proper function of pressure cap
When testing a used cap, consider that the seal may have
retained an impression left by the seat of the filler neck.
Remove, re-assemble and retest the cap several times if
necessary before rejecting the cap for a leak. When testing
a new cap, consider that the seal is new and has never been
softened by heat. Some breaking-in of the seal may be
necessary to prevent it from leaking.
set-up & Procedure:
1. Ensure the cooling system is cool and not pressurized.
Carefully remove the radiator or coolant bottle pressure cap
(Fig. 9).
2. Apply water or coolant to the rubber gasket and/or o-ring
on the cap, and assemble the cap to the cap adapter
(Fig. 10).
3. Secure one end of the clear hose to the pressure pump
using the compression nut (Fig. 11).
4. Secure the second end of the hose to the cap test adapter
using the compression nut (Fig. 12).
5. Determine the rated cap pressure. It will be printed on the
cap or in the vehicle manual. Compare this value to the
chart below (see Chart A) to determine the acceptable
pressure test range.
6. Operate the pressure pump until the cap releases pres-
sure. The pressure should relieve when the needle is in the
colored band on the gauge face corresponding to the test
range of the cap. Discard and replace the cap if it fails to
relieve pressure in the indicated range.
7. When testing is complete, release the pressure by pressing
the pressure relief lever located on pump.
8. Disconnect the components, clean, and store them
properly.
Fig. 10
Fig. 12
Fig. 9
Fig. 11
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
