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When to Change Coolant
Change coolant on the time and distance in your owner's manual, whichever comes first. Color is not a specification, and a top-up is not a flush.
When to change coolant is printed as a time limit, a distance limit, or both. Whichever comes first is the one you keep. Coolant that still looks bright can be chemically tired. Coolant that looks brown is already a problem, not a scheduled service you can postpone with a clear conscience.
The spec is the type the manual names, not the dye. Green, pink, and blue are marketing colors shops and bottles use. Mixing incompatible coolants can gel or corrode the system. If you do not know what is in the car, a drain and fill with the specified type is safer than topping up with whatever is on the shelf.
A low expansion tank is a leak, a failed cap, or a head-gasket question until someone finds out. Pouring coolant in and driving is not the service this page describes. Overheating is a reason to stop, not a reminder to update a log.
RPMBase can remind you from the next date or kilometers you save after a real flush. It does not test coolant and it does not know which chemistry your engine wants. You copy that from the book onto the row.
Time and distance, whichever comes first
Some engines want coolant service on a short traditional interval. Others specify a long-life coolant and a much longer gap. Both numbers live in the maintenance chapter for that engine, sometimes with a severe-use column. A single 'every two years' you remember from an older car is how the wrong schedule gets applied to a newer one, and the reverse.
Cars that sit still age the coolant too. If you barely drive, the year limit is the one that will arrive first. If you cover a long distance quickly, the kilometer limit wins. Write both on the row when the book gives both, the same way a timing belt is tracked by age and distance.
The service checklist on this site is a prompt to notice fluids. It is not your coolant interval. Do not let a generic tool overwrite the manual.
Color, level, and what they do not prove
Color tells you almost nothing about the additive package that is left. A rusty or oily appearance is a reason to stop and have the system inspected. Clear, pretty coolant is not proof the corrosion inhibitors are still working.
The level marks on the tank are checked cold, unless the manual says otherwise. Opening a hot cap is how people get burned. This page will not walk through that. If the level drops between checks, find the leak. A repeated top-up is a symptom you should note, not a completed flush.
Oil in the coolant, or coolant in the oil, is not a scheduled drain. It is a fault. Do not log it as 'coolant changed' and keep driving because the tank looks full again.
Flush, drain-and-fill, and a top-up
A flush and a drain-and-fill are not identical on every engine. Some service procedures want a specific bleeding routine so air does not sit in the heater or the head. The invoice should say what was done. If you only added a liter, write top-up. Do not reset the interval.
The water pump sometimes sits behind the timing cover and is replaced with the belt. That visit may include coolant because the system was opened. Log the pump and the coolant as the jobs they were. Do not assume a timing-belt invoice included fresh coolant of the right type unless the line is there.
Thermostats, caps, and hoses are the parts that fail around an old coolant. If they were replaced, name them. If they were only recommended, mark them declined. A new hose does not mean the coolant was changed.
What belongs on the coolant row
Date, odometer, the coolant spec if the invoice prints it, whether it was a flush or a top-up, and the cost. Next due is the earlier of the book's time and distance, counted from this visit. If the shop wrote a different next date, ask why before you save it.
Keep the invoice. Coolant type is the detail you will want when a different shop wants to top up in two years. A note that only says 'antifreeze' is how the wrong bottle gets poured in later.
Put the reminder on the maintenance tracker as a date, a kilometer, or both. A kilometer-only reminder misses the car that sits. A date-only reminder misses the car that does the distance early.
Season, inspection, and the jobs people swap
Coolant is not washer fluid and it is not brake fluid. Washer fluid is a winter habit. Brake fluid is hygroscopic and usually on its own time interval. Mixing those words in one row makes the seasonal plan and the real service history disagree.
An inspection may check that the level is between the marks. It rarely proves the coolant was replaced on schedule. Preparing for inspection is about passing the lane. The flush is about the engine. Log both if both happened, for different reasons.
Oil changes are frequent and easy to remember. Coolant is infrequent and easy to skip until the heater goes cold or the gauge climbs. That is why it needs its own row on the routine schedule, not a mention inside an oil note.
What the app will not decide
RPMBase will not tell you the coolant is still good because the tank looks clean, and it will not choose a brand. You confirm a row from the invoice or from work you actually did. A draft from a photo still waits for that confirmation.
Do not invent a next date to make the schedule look complete. If you do not know when the coolant was last changed, the honest log says unknown and you either test or you service it and start the clock today. A guessed year is worse than a blank.
Free covers one car and the service rows you need for this. The reminder is included. More cars are Premium. None of that measures freeze protection. A tester at a shop does.