Upon our arrival we performed the approved repairs for the replacement of the heat transfer media coil. Removed the old coil, removed both liquid line and suction line filter dryers, installed new filter dryer on liquid line, installed a piece of 7/8 copper where the suction line filter dryer was located, installed new heat transfer media coil, TXV and drain pan, removed the 90 on the suction line and properly bent the copper tubing for better connection, replaced control wiring from the condenser to under the home a little ways, installed new Armaflex on the suction line inside and out, purged with nitrogen while brazing, pressure tested to 350 psi, performed a triple evacuation service, brought the system down to a proper vacuum the introduced new clean R410a refrigerant. While adjusting the the pressures to obtain the proper sub cool value the system began to become over pressured and kept shutting down. We recovered some refrigerant from the system and began testing it again. When