You might have a bad thermostat, you might have a bad head gasket (though rare), you need a new reservoir (I wouldn't trust a repair on one that already broke - the plastic can have multiple micro-cracks through which coolant oozes, and then evaporates leaving no trace - recommend OEM from dealer - aftermarket ones are poor quality and don't last long), or you may have other leak points (hoses, new radiator defective - definitely not unheard of). Obviously the coolant is going somewhere - displacing air pockets not properly bled out, external leak, internal leak (head gasket). If thermostat is the cause and no other problems, coolant should be blown thru the cap into the overflow chamber of reservoir and no place else. Could have blockage from never changing coolant over the years, using wrong coolant, or use of certain stop leaks.
I would use the factory-prescribed bleeding technique, which involves clamping off the overflow hose and overfilling using a funnel sealed to the fill hole, then releasing the overflow hose clamp to put reserve in the overflow chamber. Not saying that's the problem, but the technique you described doesn't match the "proper" technique.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs
Last edited by peva; 03-29-2016 at 06:46 AM.