The auxiliary heater hose connections (that are routed to the rear heater under the vehicle) can develop coolant leaks.Google+
Car Problem Reports
Dodge Grand Caravan Auxillary Heater Hose Connections May Develop Coolant Leaks
Dodge Grand Caravan Problem
Average Mileage: 125,400 mi (51,000 mi - 189,000 mi)
Visitor, 2009 Dodge Grand Caravan, 51,000 mi
had coolant leak to aux heater. tracked it down to a leaky y connection directly behind the coil pack. Dealer wanted $190 for a replacement assy. Told me it can't be repaired. What I did was remove the plastic Y. and install a T fitting. On one end it goes to motor. other end I put one heater hose. I then used a small piece of heater hose to attach a 90 degree elbow to the open part of the T. This I connected to the other heater hose. Total cost. $27 including antifreeze and clamps. I bought a foot of heater hose but only used about half of it. No leaks and looks like it belongs there since my hoses aren't twisted at any weird angles. Total materials list. 1 T, 1 Elbow. 6 inches heater hose, 6 clamps and a gallon of antifreeze. No need to remove hoses from metal tubes at firewall either. Total repair time about 15 min.
Visitor, 1998 Dodge Grand Caravan, 128,000 mi
metal hose is rusted and leaking all coolant
Visitor, 2000 Dodge Grand Caravan, 168,000 mi
Underbody pipes are rusting where the heater hoses meet the pipes.
Visitor, 2002 Dodge Grand Caravan, 91,000 mi
Antifreeze loss, intermittent heat.