Typically, when thinking of car air-conditioning, our customer’s minds go straight to a re-gas as the solution. There’s no re-gas in sight with the work that’s on at CoolCar Air-Conditioning Hamilton. Here’s an outline of the vehicles in the workshop today.
Firstly, there is the 1978 Chrysler Valiant. The system is low on refrigerant but before re-gassing we need to find and fix the leak. In this case, the system is leaking from the compressor which on this occasion cannot be repaired (some compressor faults can be remedied using the existing compressor) so a new compressor will need to be fitted.
Commonly, it is the practice to simply replace the compressor and re-gas but in our case we are always interested in getting to the root cause of compressor failure.
Compressors are very robust and will keep pumping indefinitely in a car – as long as they are supplied with all of their requirements. For instance, by not overheating due to cooling fans not working or an externally blocked radiator and condenser meaning heat cannot be dumped out of the system, or low refrigerant causing insufficient cold refrigerant to come back to the compressor, or low oil because it has escaped with the refrigerant causing excess wear and heat.
Refrigerant leaks, like a leaking evaporator hiding inside the dashboard, can easily be overlooked or ignored.
PICTURED: Leaking evaporator
When an evaporator temperature sensor goes haywire it may freeze the evaporator meaning oil doesn’t migrate back to the compressor, which was the case in this Tuscon and responsible for compressor failure, hence the dashboard is out for sensor replacement. This fault can also occur when there is a blocked cabin filter as poor air flow over the evaporator can cause it to freeze.
PICTURED: Blocked cabin filter
Low refrigerant and oil to the compressor can also be caused by a shutdown thermal expansion valve (TX valve) or some other restriction in the system like when the drier fails releasing its desiccant in the system blocking up pipework. When the TX valve, which is designed to open and close, is stuck open, the compressor, which is designed only to pump gaseous refrigerant, gets a slug of liquid refrigerant which causes compressor failure and can spectacularly crack the compressor housing.
These are some of the reasons a compressor can fail when operating sub-optimally that need attention to keep the system working properly once compressor is replaced.
A 2007 Nissan Murano didn’t need re-gassing because its fault was with the blower motor and fan relay.
The 1959 Ford 500 Fairlane comes in because the compressor is noisy and the AC is not working. We need to delve into the system to find out what’s wrong.
In addition to the air-con work we also have a Mazda Premacy with a heater not working and coolant coming inside for repairs. The customer could not afford to have the leaking heater core replaced so the job is to by-pass the heater core and remove and clean and dry the carpets. The customer may return to have his heater restored when he’s more financial.
The variability of the jobs in the workshop at a point in time demonstrates why we are reluctant to provide pricing over the phone sight unseen. There really is no way of knowing what’s wrong and how much to fix it without first taking a look.
