手放したNAロードスターがまた戻ってきた！

The host explains the NA Roadster handed over a month ago is back because the repaired air conditioner stopped working again, and the car is already jacked up for inspection.

Pressing the high-pressure service valve pin shows the system is completely empty, and the previously repaired bulkhead O-ring area and compressor top are checked and found dry.

The cabin drain pipe is dry, but removing the under-cover reveals oily wetness below the compressor; condenser joints are checked and the brownish oily compressor area is deemed suspicious but inconclusive.

After cleaning with parts cleaner and charging a small amount of gas, a detergent solution shows no bubbles at the compressor, but a hissing sound and airflow reveal the leak is at the same bulkhead pipe joint repaired last time.

The fixing bolt is found properly torqued, both high- and low-pressure pipes are pulled (the low-pressure one unusually stiff), pooled oil confirms the leak side, and machined surfaces and pipe show no damage, pointing to the O-ring itself.

The host reviews the caliper-measured generic O-ring used previously and asks Gemini and ChatGPT whether the 2.62 mm cross-section was too thick, with the AIs disagreeing but raising the question of the genuine O-ring dimensions.

Realising the AC pipes are NB-spec despite the original NA compressor, the host orders genuine O-ring W32961J17 from the dealer for 264 yen and compares it to the leaked one, noting a visible size difference.

A/C oil is applied to the new O-ring, the groove cleaned, the pipe inserted straight without twisting, and the fixing bolt tightened; the pipe now slides in and out without the earlier stiffness.

The vacuum pump is run but the gauge needle fails to drop fully, indicating the leak is still present, so the host must restart diagnosis and ends the video with results promised next time.