the pipework is braised onto the pump housing, however refilling the system with refigerant after a replacement pump is fitted is a job for a professional as an exacting amount of refrigerant is required, underfilling will cause the pump to fail again and over-filling will cause the system to over-heat or even explode. more common than not it is merely the thermostat that fails and does not tell the pump to operate.
Dave Penson, March 2006
