Here's why:
* Coolant spillage: Even with careful maneuvering, some coolant will inevitably spill.
* Air pockets: Failing to properly purge the system of air after replacing the hose can lead to overheating.
* Accessibility: Working with a partially full radiator can make accessing and manipulating the hose clamps more challenging.
The small amount of time and effort saved by not draining the radiator is far outweighed by the increased risk of making a mess and potentially damaging the cooling system. Draining the radiator is the recommended and safer procedure. It's a relatively simple process requiring only basic tools.
In short, while technically *feasible*, it's not *practical* or *advisable*. Drain the radiator – it's the best approach.
