dash air charge
I think the dash air in my diesel pusher need a shot of r134a. what are the optimum pressures on the low and high side? thanks
Forum Discussion
You only need a vacuum pump if your AC system is completely out of freon. If that is the case, then you need to replace the dryer also, as well as completely evacuate the entire system. You will also probably need oil as well. But first you would have to find the leak.
If there is still freon in the system, then you can add freon without the gauges, by using just a thermometer in the dash outlet.
Add the freon slowly while watching the output air temperature, with the AC fan on high. Once the temperature reaches it's lowest temp, and starts to increase, then stop adding freon. The little bit of freon that you lose when disconnecting the hose will probably get it just right.
I've used this method for years, in all kinds of outside temperatures, and started using it when the shift was made from R12 to R134a.
If there is still freon in the system, then you can add freon without the gauges, by using just a thermometer in the dash outlet.
Add the freon slowly while watching the output air temperature, with the AC fan on high. Once the temperature reaches it's lowest temp, and starts to increase, then stop adding freon. The little bit of freon that you lose when disconnecting the hose will probably get it just right.
I've used this method for years, in all kinds of outside temperatures, and started using it when the shift was made from R12 to R134a.
