Coolant Flush (Coolant Change)

Coolant inhibitors wear out over time, so manufacturers set change intervals. Some coolants are designed to last for many years, others need more frequent changes. The system must be bled of air afterwards. Rust-coloured or oily coolant suggests corrosion or contamination that a simple flush may not fix; oil in the coolant can point to a failed oil cooler or head gasket. Some cars need a vacuum filling device to avoid air pockets. Only use coolant that meets the vehicle manufacturer's specification.

Fresh coolant restores corrosion protection and freeze protection.

Mixing incompatible coolant types can form deposits. Dispose of old coolant properly; it is toxic.