A/C System problem

I have an interesting problem with my '85-735i: the AC system has been recently recharged, and serviced with 131A. The "fat" hose coming from the air compressor, is cold when running, and the sight glass on the canister below the rad does show fluid splashing around inside. I found a broken plastic “T” at the entrance of the baseball style vacuum container (below wipers passenger side). The problem I am having is when it is relatively cool outdoors, say 60-65F., the cool air does come out of the dash vents and also is sent to the back seats, where you want it to. But when the temp is much higher outside, the cool air only comes out of the vents at the windshield defroster! Occasionally when I accelerate, the cool air will come out at the floor area, but when I have slowed to a constant speed, the air returns to the windshield. Nice to have a cool windshield, but that does not help make the passengers feel any of that nice AC. Any ideas??? Thanks in advance. JM>

beleive your close to the solution......that little ball is a vacuum tank for the IHK or 'intergrated heating/cooling' system. there are several 'fail-safes' built in one of them is in the event of a vacuum lose [ the little door servos for the IHK are vacuum operated ] you'll always have air to the windscreen [ so you can see (defog) ]. when you turn the key on [engine off] you should hear the vacuum pump on the L/F wheel house area run about 10 sec's.......if it keeps running, you've a leak in the IHK system. a hose runs from that pump to the firewall through the heater valve mount. on the other side [under the wiper] a hose tee's to that tank and to inside the car through another block. check those areas for a leak first.
IF the pump never runs, it's probably 'dead' and you'll always have poor vent flow on accel. or long hills 'til it's repaired.......FIND any leaks first, those little pumps weren't designed to run all day and they will [with a system vacuum leak] 'til they burn out......................best to you......................jb.