Air Con Stopped Working Again?
A leaking Air Con system is the most common cause of AC systems not working in vehicles.
If your air conditioning system requires frequent charging or only worked for a few days after being recharged then you almost certainly have a leak.
Recharging the system will firstly, result in more refrigerant gas being vented to the atmosphere which is damaging for both the environment and your wallet. You should book your vehicle in for a leak test.
Two methods are used to find a leaking Air Con system;
1. Vacuum Testing- leaking Air Con Systems
Most Garages perform a basic leak test using a vacuum pump. If the system holds a vacuum for a period of time, typically 5 minutes it is considered to be not leaking. However, because the system operates under pressure it makes sense that the refrigerant circuit should be under pressure when testing an Air-Con system that is leaking.
2. Pressure Testing
Leak testing with an ultraviolet lamp
To make leaking refrigerant visible under ultraviolet (UV) light, the refrigerant gas can be mixed with a special dye. Using a UV lamp makes it easier to locate refrigerant system leaks. however, this method requires the system to still be operational, and the dye to have been added during previous repairs or servicing work.
If the system is leaking or is no longer operational this method is not suitable.
Leak testing using oxygen-free nitrogen (OFN)
Because Nitrogen has a molecular structure which makes it suitable to find leaks, it is used instead of refrigerant.
The refrigerant will need to be recovered if either;
If the air conditioning system is still operational or if the system charge is too low.
Only then the system can be tested for leaks using a minimum pressure of 3.5 and up to 10 Bar with oxygen-free nitrogen (OFN).
Using a spray bottle leaks can be detected using a bubbling detergent.
leaking Air Con – Areas to check
a) All connections and pipes
b) Compressor driveshaft
c) Compressor service valves and sealing gaskets
d) Condenser and evaporator matrix tube ends
e) Receiver/drier or accumulator/drier connections
f) Pressure switches
g) Spring lock coupling connections
The most effective and environmentally responsible method is to use OFN, which is why this here at Gotboost we use the Testo 550 Digital manifold set with its built-in leak test program.