96 Astro antifreeze smell

I continually have a smell of antifreeze inside the van. My heat is fine. I do run at a lower level than full in my radiator and my overflow bottle stays empty but once my radiator finds its level it stays there. I had to have a water pump replaced about 4 months ago and the mechanic said the pressure test did not hold pressure but there are no apparent leaks. I never see any antifreeze under the vehicle. I have read about diverter valves that are notorious for leaking but I never see any issues with leaking. Lastly, may be unrelated but I cannot get heat to from the auxilliary heater in the back of the van. Help

I'd suggest you have a leaky heater core. It probably leaks under pressure, and drains out on the road thru the A/C drain.
My thoughts are it's probably small enough to fix with some rad-seal. Is it time to change the anti-freeze too? I've read that GM recommends a stop leak / water pump at change-time

Had the same problem on my '92 several years ago. Radiator seal took care of the leak