I want to get the coolant changed on my car, and was shopping around for prices. Some shops call it a ‘drain and fill’ and some call it a coolant ‘flush’. Is there a difference, and if so – which one is better?
There isa difference between a Drain & Fill and a Coolant Flush. Let’s first talk about why you would want to get your coolant changed in the first place.Why Service Your Cooling System?
Coolant is designed to perform a number of different jobs. It keeps your engine cool so that it doesn’t overheat, and also keeps your engine from freezing into a big brick of ice in the winter. It also keeps the seals and gaskets soft and supple so they are less likely to get brittle and leak, and has anti-corrosive properties in the fluid that protect the metal pieces of the engine from corroding.Just like your oil breaks down over time, so does your coolant. After about 2 years or 30,000 miles (for most cars), the coolant starts to lose its ability to protect your engine the way it was designed to. Thus, the coolant service. The purpose of servicing your coolant is to get the old stuff out and the new stuff in so that it can protect your engine the way it was intended to.
Drain & Fill
A Drain & Fill does just what is sounds like – the coolant is drained from the radiator, and filled back up with a 50/50 mixture of coolant and water. Shops have been servicing cooling systems this way for years. While this has been a traditional and accepted way of servicing a cooling system, it isn’t necessarily the most effective because the old coolant is only removed from the radiator – not the other parts of the cooling system such as the engine block and hoses.Coolant Flush
A Coolant Flush is another way of servicing a cooling system that provides a more thorough cleaning and a more complete exchange of fluid. While I can’t speak for how other shops perform their coolant flushes, I can tell you how we do it here.We first add a chemical to the cooling system that helps remove any debris that has built up in the system (rust, corrosion, etc), and then we use a machine that moves the old, dirty coolant out, and replaces it with a brand new 50/50 mix of coolant and H20. The fluid moves through the cooling at the same speed at which it would go through it under normal operating conditions (translation: it won’t damage your engine).With the extra equipment and chemicals required for this service, you will often find that this service is more expensive than the typical Drain & Fill. Our recommendation? The added expense is worth it – you’ll get a more effective cleaning of the system, and your cooling system will be better protected in the long run
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Dan Amundsen is a Master ASE Certified Technician, with over 40 years of automotive repair experience. He has been the owner of Juanita Firs 76 since 1978. He runs a true family business with his two children, three nieces, and many just-like-family employees that have been with the company for over 15 years.