80 series didnt handle the heat perfectly

Debris and baked mud between the AC heat exchanger and radiator. After 12 months it would be the first place I'd be looking if I regularly drove around up north.

Remove radiator, blow out BOTH units throughly with a powerful air compressor at exactly 90 degrees to the fins, pull out remaing seeds with tweezers and then wash with water to get the fine dust that accumulates and turns to rock hard baked terracotta when it get a few spatters of rain. GSWA Landcruisers have the AC removed for this reason.

To roughly test condition of radiator, take off both hoses, fill with water while covering the lower outlet with your hand and then quickly take it away. If the wtaer gushes out in one fast moving stream and then stops it should be OK. If it slowy flows out and seems to just taper off it will be blocked. I very much doubt the radiator would be blocked if the correct coolant was used.

I'd then get the AC gas level checked and dye tested if low.

Hi Davoe,

It was 41.7° max in Northam on Saturday.
BOM site Site Link
Maybe it was just a bit too hot and the hills made the difference.

Had your aircond iced up, hence the limited water flowing out of the drain?
I've a similar problem with my HJ61 and figure it's time for a system recheck when I can afford it. Mine ran really cold, then seemed to stop working on the hottest days. Last time it was checked the guy topped it up with new R134a gas on top of the R12 or whatever it is, which might make a difference.

Tim

sounds to me like the evaporator is blocked externally maybe go see you're air-con specialist

The sahara came std with an extra electric fan up front....a friend was in thesame position, but chose to fit an old fan from a commodore v6 up front to prove or disprove the clutchfan. It proved it, but i couldnt get the fan back off him because the air cond blew 5 degrees colder with it on...and the motor loved it too.
Another option to consider....
Andrew