if there is no radiator cap on a '97 deville how do you bleed the air out of the system while filling it with coolant

What I read earlier while looking into your other question is that you fill as best you can thru lower radiator hose then top off resivoir to full cold mark. Crank up and watch for the bubbles in the resivoir and top it off as needed. Will try to find the procedure and get you a link to it.

I believe there is a bleeder screw located on or near the Thermostat housing. Crack it loose while filling the resevior on the system ( Not running/ Cold ) and then again with it warmed up but not hot.

Mix up a couple of gallons of 60/40 DEX-COOL and water (distilled, if you're anal). Crush 3 Bar's/GM supplement tablets (ONLY tablets...no liquids) obtained from your dealer, cheap, or a large parts store, cheaper. Place the mess in the lower hose and reinstall it with the clamp in the same place as before (dents in hose). Funnel in as much of the coolant mix as possible, filling the surge tank to the COLD arrow indicator on the front side. Leave the tank cap off. Start, warm up, and check for leaks. Let it idle for 10 minutes while you watch the level in the surge tank. You should see spurts and bubbles come from the bleeder hose. When all seems well, reinstall the air deflector and lower the car. Let it cool and return the coolant to the level indicator on the tank. Dispose of the old coolant - it's poison. Go for a short drive and once again, check the coolant level. ----- found this on http://www.cadillacforums.com/