B4000 Regular Cab 4WD V6-4.0L OHV (1997)
Radiator Cap: Testing and Inspection
RADIATOR CAP VALVE
1. Remove all foreign matter (such as water residue) from between the radiator cap valve and the valve seat.
2. Attach the radiator cap to a radiator cap tester (commercially available) and apply pressure gradually to 83 kPa (12 psi).
3. Verify that the pressure is held for at least 10 seconds.
NEGATIVE PRESSURE VALVE
1. Pull the negative pressure valve to open it. Verify that it closes completely when released.
2. Check for damage of the contact surfaces and for cracked and deformed seal packing.
3. Replace the radiator cap if necessary.
