Thread: D4 a/c not cooling

The message was that 600g was used, but perhaps the equivalent weight of hychill.

It was stated that there are no leaks.

Fingers crossed it's a blocked dryer and they didn't put in 600g of Hychill.

I'll get that checked.

Edit: Would overfilling with Hychill cause damage?

The mechaninc used the Hychill specs for the 3.0 D4 which is 600g R134A or 180g of Minus 30.

Originally Posted by Graeme

I'll get that checked.

Edit: Would overfilling with Hychill cause damage?

It would send the Head Pressure sky high.If the HP cut out is operating it should stop any damage,but better not to operate it at all,as cycling on the HP switch,and operating at very high head pressures is not ideal.
They are often set very high on Auto air systems,often just over 400PSI,which seems rediculously high for 134A/Hychill,but the settings seem the norm on many different brands of vehicles.

FWIW,our newer Hi Aces and Hi Luxs ACs operate on R1234YF

Originally Posted by scarry

They are often set very high on Auto air systems,often just over 400PSI

The D3 doesn't throttle back the compressor until 479PSI. If my pt chart is correct that's about 90 degrees for r134a.

Originally Posted by BradC

The D3 doesn't throttle back the compressor until 479PSI. If my pt chart is correct that's about 90 degrees for r134a.

In refrigeration we set 134 HP cut out on 240 to 260 PSI,even in a very hot day it will usually run well under 200PSI.
Cooler weather often 120 to 160PSI,particulary systems that are capillery,operating around -15 to -10 SST.

Then again your commercial refrigeration condenser will be in open air with the fan going flat out, not sitting up the arse of a diesel bus on a 42C day at the lights with the viscous fan doing less than 1000rpm.

I've seen > 26bar (~380PSI) sitting at the lights. Usually the evap temperature will start to climb so I'll lean on the throttle a bit to get the fan & compressor revs up. Happy to trade fuel for comfort.