Hey guys,
I’m a novice with automotive AC systems and wanted to get some opinions before throwing parts at this.
Vehicle is a 2010 Toyota Avalon (R-134a system).
❄️ Issue:
AC cooling is inconsistent. When I bought the car about a month ago, it worked roughly 70% of the time, but would occasionally not blow cold. After attempting to recharge it, the issue got worse—now it works maybe 20% of the time.
During the recharge, I noticed the coupler wasn’t fully seated, so it’s possible I introduced air into the system.
📊 Gauge Readings (engine idling ~5 minutes):
Low side: ~90 psi
High side: ~127 psi
Ambient: ~59°F (15°C)
🔍 What I’ve checked:
Compressor clutch engages and stays engaged (even when not cooling)
Radiator/condenser fans run properly
Condenser is clean (rinsed)
Cabin air filter is new/clean
Blend door seems functional (can switch hot ↔ ambient air)
🧠 Observations:
Very high low-side pressure
Relatively low high-side pressure
Minimal pressure differential
❓ Question:
Given the likely introduction of air and improper recharge, does it make sense to:
👉 Recover, vacuum, and recharge the system to spec first before diagnosing further?
Or do these pressure readings point more strongly toward something like a weak compressor or restriction?