Metering the Refrigerant for Peak Cooling
The Expansion Valve (TXV) or Orifice Tube (OT) acts as the metering device for your AC system. Its crucial job is to control the amount of liquid refrigerant entering the evaporator. This allows the refrigerant to rapidly drop pressure, vaporise, and absorb heat, the core cooling process.
When this component fails—often due to clogging from debris or moisture, or mechanical failure of the TXV sensor—it directly causes major cooling problems:
- Underfeeding: Not enough cold air, or cooling that is intermittent.
- Overfeeding: Causes the evaporator to freeze up, leading to a total loss of airflow.
In Pretoria's heat, a faulty metering device quickly makes your car unbearably hot. We accurately diagnose whether the valve is the source of the blockage or failure.
Replacement and System Flushes
Replacing the expansion valve or orifice tube requires expert knowledge and adherence to strict protocols, as it involves opening the sealed refrigerant system. Our service includes:
- Accurate Diagnosis: Using pressure readings to confirm restricted flow through the valve/tube.
- System Evacuation: Safely recovering all old refrigerant and oil.
- Component Replacement: Careful removal and installation of the new valve or tube.
- System Flush (if necessary): Thoroughly flushing the system to remove contaminants that caused the original blockage.
We finish the job with a precision regas and performance test to ensure the new component is metering refrigerant perfectly, restoring your vehicle’s factory-spec cooling efficiency. Rely on our Pretoria team for specialised component replacements that last.