Mysterious AC Problem on a Rare 1996 Toyota RAV4: Diagnosis and Repair

Diagnosing the AC Issue

• 💡 The 1996 Toyota RAV4 2-door Japanese import presented with a peculiar AC problem: it would start working and then slowly fade and stop.
• 🎯 Initial gauge readings showed a normal high side but a low side that was too low, eventually dipping into a vacuum and causing the AC to stop working.
• ⚠️ This behavior, indicated by the low-side line freezing over, suggested either a restriction in the system or an issue with the expansion valve or receiver dryer.

Receiver Dryer Replacement Attempt

• 🔑 The technician suspected the receiver dryer due to the freezing line, as it's more accessible than the expansion valve located behind the dash.
• 🛠️ Accessing the receiver dryer required removing the air filter box and coolant bottle, revealing a non-original, aftermarket part.
• 🚫 It's noted that aftermarket receiver dryers are generally not recommended for Toyotas, leading to the decision to replace it with an OEM part.
• ⏳ After replacing the receiver dryer, the system was put under a 25-minute vacuum to remove moisture before recharging.

Expansion Valve Replacement and Reassembly

• 📉 Post-replacement testing showed the AC still not functioning correctly, with the low side again frosting over and pulling a vacuum, indicating the receiver dryer was not the sole issue.
• ⚙️ The next step involved accessing the expansion valve, which required significant disassembly of the dashboard components, even on this right-hand drive model.
• ⚠️ A key challenge was the tight space and the need to carefully maneuver the evaporator box out, complicated by existing aftermarket radio installations and manual inaccuracies.
• 🧩 The old expansion valve was removed, and a new, updated OEM part was installed, along with new O-rings where possible, though some were discontinued.

Final Testing and Additional Repairs

• ⚡ After reassembly and recharging, the AC compressor began to cycle correctly, and the low-side line no longer frosted over, indicating the AC system was likely fixed.
• 🩹 A minor issue arose with a stuck high-side Schrader valve, which was resolved by removing debris, though some refrigerant was lost in the process.
• 🚗 The video also briefly touches on other maintenance items for the RAV4, including a leaking valve cover, distributor O-ring, and the need for new spark plugs and wires, noting the timing belt is due but not critical as it's a non-interference engine.
• 🧐 The technician plans to further test the AC performance on a hotter day to confirm the charge level and overall system stability.