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. Slowly loosen cap to first stop to relieve pressure before removing completely.

NOTE: These tests apply only to John Deere radiators. For other brands, see manufacturers literature.

Test Radiator Cap

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

2. Pressurize cap to specification listed. Gauge should hold pressure for 10 seconds at least to pressure listed if cap is acceptable.

   If gauge does not hold pressure, replace radiator cap.

   Item	Measurement	Specification
   Radiator Cap Holding Pressure (Not Opening For 10 Seconds)	Pressure	70 kPa (0.7 bar) (10 psi)

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

Test Cooling System

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

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 specification listed for radiator cap.

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 engine distributor or servicing dealer correct this problem immediately.