Approximately 60% of system failure is down to loss of refrigerant charge where the charge has been lost naturally. The remaining 40% of failures can be one or more of many that occur. It is therefore a gamble to simply assume that the system just needs re-gassing and this approach can become very expensive for you - the customer.
It is true that some faults cannot be determined without running the system with a full charge of gas and that not all tests can be considered conclusive. However, contrary to the convenient popular myth that diagnosis is not possible until the system is properly charged there are many faults that can be detected prior to re-filling with gas. These faults range from simple blown fuses to compressor failure. It is our aim to learn as much about the a/c in your vehicle as possible before re-filling so that you can make an informed choices and minimise costs to you. You may decide not to replace a faulty condenser or failed compressor - a decision better made before you have paid for a re-gas and not after. In order to avoid unnecessary work/costs it is essential that a proper diagnosis of the fault is carried out prior to re-gassing. While a pressure test should not be considered conclusive the test together with the function checks are sensible precautions that will determine most faults that you may have on a vehicle’s a/c system and are carried out on every vehicle that we service without exception.
Our standard mobile service includes:
10 Minute Pressure test
This 140psi nitrogen pressure test will show up “simple” leaks
Initial function check
The compressor, compressor clutch, command and executive electrical circuits are checked for function, the low pressure sensor/switch is checked and the expansion device is checked for blockage.
30 minute Vacuum
Essential for the removal of any damaging moisture or air present in the system
Re-gassing as required
Fresh gas charge, either R134a or HFO-1234yf, to the correct level for your vehicle ensures optimum performance and compressor life
Refrigerant Oil charge as required
Any oil removed is replaced ounce for ounce
Operating pressures check
Operating pressures will tell us how well your system is performing and can give an indication of potential faults
Condenser air flow check
Restricted air flow will affect performance considerably
Auxiliary fan check
Auxiliary fan failure will reduce performance and can damage the system/compressor
Check service ports and caps
It is quite common for service port shraeder valves to leak. Correctly fitting caps are there to stop the refrigerant from leaking out
Service options - in detail
Nitrogen pressure test
The molecules of nitrogen are smaller than that of refrigerant and it can be easier, in a discharged system, to detect a leak with nitrogen than using refrigerant. It is also better for the environment as any refrigerant used for leak detection will escape to the atmosphere. This test will show up simple leaks but may not reveal complex leaks such as those of a temperature, vibration or pressure dependent nature.
30 minute vacuum
30 minutes is the minimum time recommended for the system to be subject to a vacuum by most manufacturers. It is essential for the removal of air or moisture that has entered the system. Failure to remove air can result in poor or non existent performance or physical damage including destruction of the compressor or condenser. Moisture will react with the refrigerant resulting in acid production which, in turn, will corrode the system and cause premature failure of components. One of the most common causes of poor performance is insufficient vacuum time.
The most common cause for an air-con system to fail is low gas. All systems will leak gas over time and when the pressures drop to a predetermined level the system, with some exceptions, will lock out in order to protect the compressor from further exposure to damage. Running a system with a low gas charge will use more fuel than one that is correctly charged and can increase compressor wear due to overheating and low lubrication. We remove any remaining gas correctly and charge, to the correct weight, with fresh gas. Overcharging with refrigerant, even by a small amount, can destroy a compressor or the condenser and can easily happen when charging without weighing refrigerant into the system or topping up a system with a residual charge.
UV Dye injection
When leaks occur on air-con systems they can be very time consuming, and therefore costly, to find. One method that has become very popular within the industry is the use of ultraviolet fluorescing dyes that mix with the refrigerant oil. When a leak occurs the dye will leak out with the oil and refrigerant. The leak can be found by shining an ultra violet lamp on the components of the system. This has proved to be a very effective means of finding and or confirming leaks and can bring the cost of repairs down considerably.
The oil in the system is essential for correct lubrication of the compressor and compressor shaft seal. It can be damaged by the presence of moisture. The oil will also carry signs of acid build up in the system that will eat away at the components of the air-con and will, in the long term, cause severe damage. Analysing the oil in a system can reveal the “health” of it and remedial action can be taken to reduce expensive repairs later.
For small leaks in a charged system an electronic, sniffer type, leak detector can be used to pinpoint the leak. Electronic leak detectors are very sensitive and accurate. Ultrasonic, ultraviolet and hydrogen leak detection methods are also employed.
Barrier hose repair
Air con hose assemblies can, when damaged, be expensive to replace. In addition to the normal mobile services, hose and tube repair is also available. Damaged barrier hose sections can be re-fabricated using a portable hydraulic press. All sizes of Standard and reduced barrier hose and fittings are stocked. A wide range of aluminium braze fittings and tube is also stocked in order that many a/c hose assemblies can be repaired rather than be replaced.
With the exception of the very latest vehicles the only gas that is approved for use in cars is R134a. Other gasses, including hydrocarbon gasses available from hardware stores, have been used by unscrupulous mechanics/DIYers to get air-con systems working. Some of these gasses will work well in the short term but will, over time, cause damage to the system. Unrefined hydrocarbons will not only cause serious damage to a system in the medium to long term but are extremely flammable and in the right circumstances can explode. Certification of the refrigerant in an air-con system will give peace of mind to the owner of a second hand vehicle and will show a prospective buyer of a vehicle that the correct refrigerant has been used.
The evaporator is housed in the heater plenum of the car. This damp and dark environment collects pollen, dust and various organic particles. Over time bacteria will breed together with viruses and fungi. When the vehicle has been left on a hot day and the engine started a foul smell, similar to old wellington boots, from the heater vents will indicate the presence of an infestation. We can apply a pharmaceutical grade biocidal treatment that will clean and coat the surface of the evaporator in order to help prevent a reoccurrence.
A full range of components are available for fitting including - Condensers, Receiver/dryers, Compressors, Evaporators and Hose/tube assemblies. Where it is not practical to replace any item at your premises then workshop facilities are available.
All services are subject to availability and may be withdrawn at any time without notice.