You can reach the expert, George @ Extreme Outback Products at (866) 447-7711 or visit his web site at extremeoutback.com . George is a true gentleman to deal with and will give you straight answers (as is/will Heber at SMB West).
I'm not entirely sure of the benefit the "tee" will provide, if the system is working properly. Your system does not sound like it is working right. There is a high pressure cut-off switch which I believe is set at 140 psi. If I remember correctly, the 2 gallon tank should fill in about 3-4 minutes at lower elevations. There have been some compressors that needed the head tighened/replaced, but most of the time a compressor would run continuously was because of leaks at the fittings.
FYI, the 80 amp circuit breaker for the ExtremeAire is usually located under the van on the passenger side, behind the side door step, outboard on the Ford frame. (There were many calls on where it was located, so I thought I'd throw this bit of info in too.)