When troubleshooting a 2000 Dodge Caravan for a cooling leak, it is a good idea to explore the number of possibilities. The engine has freeze plugs in the block on both sides and in the rear between the transmission and the engine. Freeze plugs are designed to come out of the block in the event the engine coolant freezes and expands. They prevent the block from cracking. More possibilities are the intake manifold, the heater core, the heater hoses and radiator hoses, radiator cap, thermostat, water pump, coolant reservoir and the radiator.
Remove the radiator cap on a cold radiator. Check the spring and the gasket for irregularities.
Fill the radiator with water for testing.
Install the pressure tester and pump it up to no more than 17 pounds. The radiator is now pressurized with a slightly higher pressure than would be present in normal operation.
Look at all the spots mentioned above for leaks created by the extra pressure. Look at the bottom of the van and see if any coolant is dripping. If so, follow it upward to locate the source. Check the radiator for leaks on the top plastic tank and on the sides. Leaks in the heater core show up as a leak at the firewall on the passenger side. Coolant flows from the air conditioning condensation drain hose coming out of the firewall.
