There's a leak in the left rear when it gets cold. Above 60°, it's solid. In the high 40s it's slow, as much 1/4" per hour. In the low 30s it's fast, as much as 1" per hour. The auxiliary air tank holds reasonably well unless it is below 30° and then it will leak out if the compressor is off.

Some history: Prevost Dallas looked at it a month ago. I told them it dropped only when cold. It was 65° and they found nothing except a very slow leak at a fitting on the air tank. They fixed that. I'm going back to them in a couple of days and would really like to tell them where to look. It will be cold there so maybe it will be obvious, but I'd rather give them advice than take theirs. The tech said the leak could be anywhere and the coach would drop at a random location rather than a specific corner. Didn't sound right to me.

Six months ago, Prevost Dallas replaced a couple of 5-way valves and 4 quick-fill tank drain valves back there. A year before that, they replaced a Burkett valve with a 3-way 2-position Norgren.

Anyway, I'm clueless, except for the facts. Can you help?