Coolant drain and refill
Antifreeze is not only about freezing — it is what stops the engine corroding from the inside.
Coolant does three jobs: it carries heat away, it lowers the freezing point and it stops the inside of the engine corroding. The corrosion inhibitors are used up after a few years, and from then on the coolant is quietly attacking the water pump, the radiator and the head gasket.
That is why it has a replacement interval even though nothing appears to be wrong. Replacing coolant is cheap. Replacing a head gasket is not.
How you know you need it
- The coolant is brown or rusty rather than its original colour
- Four or five years since it was last done
- The temperature gauge sits higher than it used to
- You are topping up more often than you should be — that is a leak, and we will find it
What we actually do
- 1 System drained cold, and the old coolant taken away for proper disposal
- 2 Flushed where the condition calls for it
- 3 Refilled with the correct type for your engine — the colours are not interchangeable
- 4 System bled of air, which is what causes hot spots and false temperature readings
- 5 Heater and gauge checked on a road test
Questions about this job
Can I just top it up with water?
In an emergency, briefly. Water alone has no corrosion protection and freezes, so it needs putting right afterwards.
Does the colour matter?
Yes. The colours mark different chemistries, and mixing some of them turns the coolant to gel. We use the type your engine specifies.
How often?
Typically every four to five years. Check the handbook, or tell us the car and we will look it up.
Coolant drain and refill — in Westhampton
118 Mill Lane, Westhampton, Westshire, WX1 4AB. Open seven days, Sunday included.