What is the purpose of the coolant reservoir?

Answer by  Amber40 (24961)

The reason for the use of a reservoir in a cooling system is to catch overflow. Hot coolant can expand and take up more space in the system. If it simply ran out of the system when the engine cooled back down it would be low on coolant. With the reservoir it can flow back into the system as needed.

Answer by  Amber40 (24961)

I most system it is simply used to catch coolant that flows out of the system as it heats up. This prevents coolant from dropping on the road or being wasted. Some cooling systems require a reservoir higher up to keep air out of the system.

Answer by  Brit7any (115)

It is there to keep the car from over heating. You must keep coolant or water in the reservoir or the car will over heat causing damage to your engine.

Answer by  nt17 (125)

Reservoirs "catch" and hold coolant as the engine operates. Various conditions such as outside temperature and vehicle loads and engine speeds cause the engine to increase or decrease coolant levels.