>
>If it's not air in the system, it could be that your heater core is
>all plugged up with crud.
>You really should get full heat at full fan.

Naw, it don't work for me neither. I have the same symptoms, worse with age, in
an '85 and '87, even when freshly burped. The '85 was like this in '86 when 
'new' to me. I can overcool the air on fan setting '3'. ('member, it's -20C 
outside here around now!) I usually drive with front fan on '1' or off, and 
rear on '2'. I also close down the slider settings on the highway to keep 
hot air coming in. BTW, front fan provides hottest air to feet, so my 
burping is less than perfect! Leakage, drying out the upper portion of the 
heater core from time to time, may well be allowing fuzzy rusties to build 
up, further aggravating the situation, despite burping. I will clean/purge 
the '87 next spring, for full heat in August!  My wife wants to know why I 
keep the heat on full in fall/spring. It's because I HAVE heat, unlike many 
previous buses. I revel in it!   tim s.