[bazar01]

It is best to totally evacuate the remaining R134A refrigerant with a vacuum pump since you already have the gauge manifold set. You need to evacuate at least 3 hours with the vacuum pump on. Once you reach 29-30 inches Hg, turn off the vacuum pump, close the gauge manifold and let it sit for a few hours and see if the vacuum holds. If on the other hand the vacuum pump keeps running but it cannot pump it down to at least 20 inches Hg, the system has a big leak.

Once the vacuum holds for a few hours, charge the system with the recommended amount. On the engine decal, it will state the R134A charging weight.

After charging, you have to monitor how long it will hold the correct charge. It can take days, weeks or months deoending on the leak. You will normally feel when it starts blowing warmer supply air at the vents. Then you need to start pressurizing the system again and use a sniffer to check for minute leaks and soap bubble test the fittings for big leaks.

It is not unusual not to find any leakage from external components and fittings. The weakest ac component is the evaporator which is always the culprit. And replacing it is not easy.

good luck.