Junpai turned to Caton on a hot day.

What you want to ask is why Junpai turned to Caton on a hot day? The reasons are insufficient lubrication of steering system and wear of steering system parts.

1. Insufficient lubrication of steering system: the hot weather makes the lubricating oil thinner, which makes the lubrication effect of steering system worse and leads to steering jamming.

2. Wear of steering system parts: After long-term use, steering system parts will wear, such as steering transmission mechanism and steering pump.