Iceman Cooling Journal

Many SUV’s and vans have standard or optional rear air conditioning systems that rely on underbody lines to move refrigerant to and from the rear evaporator.   Often these lines will fail due to pitting corrosion while operating in northern climates that use salt for deicing the roads.   The cost to replace a line to make the rear AC system option functional may be more than a customer can justify .   A less costly option is to eliminate the rear AC circuit completely. Once the rear circuit is eliminated, and the front part of the system is confirmed to be leak free, the system can be appropriately recharged with refrigerant and oil.

To eliminate the rear AC lines one should terminate each line as close to the front of the vehicle as possible thereby reducing the possibility of leaks from any remaining line sections.   In many cases this can be accomplished using cap off kits designed to interface with the original equipment connections at the front connection “Y” sections.   These kits are very reliable and easy to install since they do not require any cutting or welding of the lines that are being terminated. Cap-off-kits for many vehicles are offered by Auto Air and Accessories Inc. of Blaine MN.  One of the most popular cap-off kits illustrated below is often used as an alternative to repairing leaks at the rear evaporator on Chrysler mini-vans.

A second option for eliminating the rear AC circuit is to cut the lines at the damaged point or just behind the front “Y” joint connection and then install line terminators.   A popular type of terminator, (Smart Splice Line Terminator^TM by Airsept), sold in both English and metric lines sizes, incorporates specially designed compression fittings.   When using these types of terminators one should install them as close to the front of the vehicle as possible to reduce refrigerant and oil pooling in the rear AC lines.  One needs to accurately measure both the liquid and suction line sizes before selecting the mating fittings.   Sometimes one of the lines will be an English size and the other will be a metric size and it is important to only use the fittings specifically designed for the lines being terminated.   A typical terminator kit is illustrated in the following photo.  One will need a terminator for the liquid and another for the suction line.

A final option is to cut the lines, flatten the ends and TIG weld them closed.   This option is the least desirable for most shops because they would need to out-source the TIG welding.

Regardless of which of the above options is selected, the installer must consider the reduced system volume and compensate by reducing the refrigerant and oil charge.   If all of the rear circuit has been eliminated due to the location of the line terminations, then the manufacturer’s specifications for a front AC only system would provide a close approximation for the recharge specifications.   And as with all AC repairs, one should check for leaks after the system has been in use for a short period of time and again annually to assure that the system will continue to meet the customer’s expectations for comfort and reliability.