The quick-connect fittings for the heater hoses tend to leak engine coolant. This problem commonly occurs because the metal housing has become brittle, which can break and cause leaks.Google+
Car Problem Reports
GMC Suburban 1500 Quick-Connect Fittings For Heater Hoses May Leak Engine Coolant
GMC Suburban 1500 Problem
Average Mileage: 177,972 mi (125,000 mi - 217,000 mi)
Visitor, 1994 GMC Suburban 1500, 208,000 mi
Engine leaking coolant, white steam in exhaust. replaced intake manifold gasket and bad coolant hose connector fitting.
Visitor, 1999 GMC Suburban 1500, 151,253 mi
Took it to mechanics shop, there were other issues with it, don't if I will keep it... :(
Visitor, 1997 GMC Suburban 1500, 182,000 mi
slight coolant leak for about 6 days, then on cold engine start- threaded end of heater hose adapter broke off-hope I can fix it for cheap (ain't nothing cheap any more, but I can still hope
Visitor, 1997 GMC Suburban 1500, 200,000 mi
I tried to replace it when it started leaking. Ended up breaking off in the manifold. Had a wicked time getting the rest out of the manifold.
happened to me ,then when I tried to remove it I broke the cast aluminum manifold,cost manifold 50.00 gasket set50.00 plus labor uuurrg