I've worked with AC for a bit and do all my own mechanic work however this one is getting confusing mostly because I can't find a proper schematic of where the components are. Usually I'd just follow a line and take it all apart. But this is my mom's van. A 2012 model

When trying to add to the system for her noticed it immediately blasted out the front expansion valve . I have now replaced it. It no longer has any issue. However while doing vacuum of, it would not hold it. It would in fact leak out the same rate but I cannot find where.

Any help is appreciated and I apologize if it's a common question.

Thanks

 

Inject some dye in the system and charge it with nitrogen this will make the leaks visible. We use to do this when checking for leaks on coils in large A/C units and also when brazing the coils.