AIR CON REGAS

1 Regassing an air con system requires the use of a special machine to remove any remaining gas and lubricating oil, vacuum the system out, test for leaks, add new oil and a UV trace to detect any leakage before finally recharging the system with the correct amount of R134a tetrafluoroethane refrigerant.

2 The first job was to locate the system’s high- and low-pressure Schrader valves and remove the caps. Finding these valves can be tricky as one can sometimes be located under a wheelarch liner. 3 The valves on our X-Type were easy to find located close together at the rear of the bulkhead on the driver’s side. Once the dust caps had been removed the high- and lowpressure pipes from the machine were screwed in place.

4 As well as entering the car’s registration number into the recharging machine to find out how much gas in grams our system required, Chris double-checked the amount on the workshop’s database.

5 With the correct figures entered into the machine the regassing program finally got underway. Chris reckons a typical air con system naturally loses at least 10 per cent of gas every year. 6 So it was no surprise to discover the amount of gas recovered from our Jaguar was zero. Air con systems have a relay that cuts out the compressor if the pressure falls due to a lack of gas. 7 Each stage of the operation was recorded on a till roll-style slip of paper and the good news was that the system on our Jaguar passed the 200 second pressure test with flying colours. 8 With the system refilled with fresh refrigerant and a dose of UV leak detecting fluid, pushing the button on the dashboard immediately fired up the compressor… 9 …and the result was a healthy blast of icy cold air from all the vents. We’ll let the system settle down and go over all the pipework with an ultra violet light to check for any leaks.