Land Rover Defender High side Too High

[mistercool]

Hi everyone,

I worked on a Land Rover Defender today which had the quite rare AC fitted. I've been doing A/C for 10 years and never come across this problem before.

I refilled it with R134a gas - vacuumed it and refilled through the low side. The car takes 700gms + or - 50gms

As the amount of gas that had gone in neared 700gms the high side was getting near 380psi and 80 degrees C. The system was working in that the low side pipes were nice and cold and there was cold air in the cabin. Low side pressure was normal - between 35 and 40 psi.

The ambient temperature was about 20 degrees C.

The (quite small) electric fan on the front of the condenser was spinning quickly and the viscous fan behind the coolant radiator was also running.


The gap between the condenser and radiator was completely clear and not blocked.


The condenser is the old fashioned style so not a parallel flow unit but the type that runs in a short of continuous "S" shape from top to bottom. The condenser had seen better days and some cooling fins were missing on the bottom two rows.


Any ideas what could be wrong? There is no air in there, it is definitely not overfilled and there is no restriction to the airflow around the condenser. I don't think the condenser being in poor shape would cause this fault but I could be wrong.

Thanks in advance.

[Dougflas]

mist the condenser with a water hose. If high side drops rapidly, there may be an air flow across the condenser or the condenser is not doing its job problem.