I have a 2000 Sienna 5 door minivan. There is a secondary rear AC with an evaporator & blower located on the passenger side, far rear side panel.

I am inquiring if this rear AC can be disconnected. There are low & high metal lines going to the rear AC beneath the vehicle, with couplers under the front passenger underbody area. The couplers are brass.

Can they be capped and not adversely affect front cabin AC? A reduced amount of refrigerant would certainly have to be used......it takes 48 oz already.

Reason for this is a possible leak of the rear evaporator and I've never used the rear AC.

Opinions or experience with such a notion? Please let me know what you think.

if you disconnect you may have some problems since the a/c systems are designed for certain applications, what could happens is that the refrigerant cycle will be altered and won't work that way it's supposed to work. if you will disconnect the rear system, you will need to take out some oil from the compressor, check spec. for you compressor, most of the times, the compressor have a label that indicates you what amount of oil and refrigerant you will need to add or subtract for double or single units. once you take out the correct amount of oil, just charge you system until it reach normal pressure. if it is r134a, the low side should read around 32psi, and high side around 180-200, that depends on the current ambient temperature and vehicle cooling system. hope this info help you.