I just replaced the water pump in my van. Checked the hoses, thermostat etc. They are fine. I keep getting a hissing from the rear heater, and the carpet gets wet and steam escapes from the rear heater. I'm putting 2 gallons of water/coolant in it every day. What could be the problem? Is it an expensive fix? Thanks.
Rear heater on 1994 GMC Safari
by Visitor in Powhatan, VA on April 10, 2010
ANSWER by Visitor , November 09, 2010
sounds like your rear heater core has a leak