Pressure Testing Cooling System

RG6557-UN-20JAN93

Test Radiator Cap

RG6558-UN-20JAN93

Test Cooling System

CAUTION: Explosive release of fluids from pressurized cooling system can cause serious burns.

Shut off engine. Only remove filler cap when cool enough to touch with bare hands. To relieve pressure before completely removing, slowly loosen the cap to the first stop.

Test Radiator Cap

1. Remove radiator cap and attach to D05104ST Tester as shown.

2. Pressurize cap to following specifications.¹. Gauge should hold pressure for 10 seconds within the normal range if cap is acceptable.

   Item	Measurement	Specification
   Radiator Cap	Minimum Test Pressure	124 kPa (1.24 bar) (18 psi)

   If gauge does not hold pressure, replace radiator cap.

3. Remove the cap from gauge, turn it 180°, and retest cap. This verifies that's the first measurement was accurate.

Test Cooling System for Leaks

NOTE: Engine should be warmed up to test overall cooling system for leaks.

1. Allow engine to cool, then carefully remove radiator cap.

2. Fill radiator with coolant to the normal operating level.

3. IMPORTANT: DO NOT apply excessive pressure to cooling system; doing so may damage radiator and hoses.

   Connect gauge and adapter to radiator filler neck. Pressurize cooling system to the following specifications¹.

   Item	Measurement	Specification
   Cooling System	Minimum Test Pressure	124 kPa (1.24 bar) (18 psi)

4. With pressure applied, check all cooling system hose connections, radiator, and overall engine for leaks.

   If leakage is detected, correct as necessary and pressure test system again.

   If no leakage is detected, but the gauge indicated a drop in pressure, coolant may be leaking internally within the system or at the block-to-head gasket. Have your servicing dealer or distributor correct this problem immediately.