overheating (sometimes)

[jackson.mcbreen]

Hey, I'm new and just wondering if anyone could help sort my surf out.
I have a 1996 kzn 185 1kz te and having problems with it overheating. It runs fine in the city and on the open road and never overheats and then when i take it up a gravel hill on a hot day it heats up and i get the auto trans temp lights on, I've replaced the radiator and it didn't help so any suggestions greatly appreciated thanks.

[tashtego]

I would replace the viscous fan if you haven't done it already. It's notorious for the silicon oil degrading and then not working properly. Roughtrax sell it. Cheers