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I vacuumed out all of my r134a to fully remove and then replace all of the refrigerant.
When the compressor turns on the low pressure side drops to a vacuum when filling. If I turn the AC off it starts gaining pressure on the low side again, like when I am filling it.
Evaporator issue or expansion valve stuck closed? Is there a clog in the line? Frozen refrigerant?
8 ounces isn't much.
I would expect both the low side and high side pressures to increase as the refrigerant charge approaches the correct amount.
Yeah I think 28oz is the max. Here is a picture from when I was just refilling it, but then the high side was rising past like 250 and it was 70 degrees out, and I didn't know how much was already in there so I just vacuumed everything out and started over, that's when it started going to -25 on the low side when trying to fill it.
Oct 11, 2025 | 02:39 PM
