What kind of failures ? Heat pumps get bad reversing valves, compressors get bad valves period. If it is not installed properly that happens alot more.. At best, before the system is filled, flushed and sealed it should be on a vacuum pump overnight.

If your problems are electrical that is much easier to deal with. Also, don't brush and disturb those evaporator and condenser coils. If they clog up you either need filters or something to keep the gunk out, but if you have to clean them use compressed air.