Mityvac MV4525 COOLING SYSTEM TEST & REFILL KIT - Manual (Page 13)

Cap Pressure Test
For diagnosing:
Proper function of pressure cap
Set-up & Procedure:
1. Ensure the cooling system is cool and not pressurized. Carefully
remove the radiator or coolant bottle pressure cap.
2. Select the correct Cap Adapter for the application. Refer to the
Adapter Selection Guide included in the kit.
3. Apply water or coolant to the rubber gasket and/or o-ring on the
cap, and install the cap onto the adapter (Fig. 35).
4. Install the Valve Coupler onto the Cap Adapter using the
quick-connect. Make sure the quick-connect sleeve snaps
forward to lock the connection (Fig. 36).
5. Install the Coupler Plug into the top of the Valve Coupler and
tighten the threaded cap securely to form an airtight seal (Fig. 37).
6. Connect the Compound Gauge to the quick-connect labeled
“Gauge” extending from the Valve Coupler. Note: It may be more
convenient to install an Extension Hose between the Valve
Coupler and the Gauge (Fig. 38).
7. Connect the Pressure Pump to the quick-connect labeled
“Pressure/Vacuum” extending from the Valve Coupler. Note: It
may be more convenient to install an Extension Hose between the
Valve Coupler and the Pump (Fig. 39).
8. Ensure the Shuttle Valve on the Valve Coupler is shifted to the
“Closed” position (Fig. 40).
9. Determine the rated cap pressure. It will be printed on the cap or
in the vehicle manual. Compare this value to the chart (see chart
A) to determine the acceptable pressure test range.
10. Operate the Pressure Pump until the cap releases pressure. The
pressure should relieve when the arrow is in the colored band on
the gauge face corresponding to the test range of the cap.
11. When testing is complete, shift the Shuttle Valve to the “Open”
position to relieve the pressure (Fig. 41).
12. Disconnect the components, clean, and store them properly.
Form 822947 Page Number - 13
Fig. 36
Fig. 38
Fig. 40
Fig. 41
Fig. 35
Fig. 37
Fig. 39
Chart A: Cooling System Cap Pressure Test Ranges
Rated Pressure (PSI) Pressure Test Range (PSI)
4 3 - 5
7 6 - 8
10 9 - 11
13 or 14 12 - 16
15 or 16 14 - 18
18 16 - 20
20 18 - 22
30 28 - 30