Text Box: Step 1: remove the old evaporator. Always use a wrench on both ends of the fitting to compensate for the torque when backing off the old connections. Here, the new RennAire High Efficiency Serpentine Evaporator is shown as it is delivered with the expansion valve and insulation tape already installed. Note the RennAire evaporator connections are in precisely the same location and have the same orientation as the stock unit.