Anti Freeze

[Chris KC]

Andrew, anti-freeze is a consumable, just the same as oil or brake fluid. Most folks get a fairly good innings out of it - but after 2 or 3 years it really wants replacing.

Whilst I thoroughly understand thrifty instincts, it's the (disposable) fluid which keeps your cooling system in good nick for years to come.

Chris, it doesn't seem acceptable to just replace it every couple of years. Using up natural resources, lots of processing and transport, then how do we dispose of it? If you google 'dispose of antifreeze' it seems that many people can't find a solution.

Frequent changing of oil and brake fluid also bothers me. My last 'modern' we had the same brake fluid in for 17 years, and changed the engine oil every 20,000 miles. Probably people will say this was wrong, but it saved a lot of resources.

On the subject of oil Andrew, I don't follow 1930's recommendations - I'm using modern multigrade oil and a full-flow filter and I change it once a year (in the Seven) at most.

As far as anti-freeze is concerned, then simply don't use it - I have never used anti-freeze in an Austin Seven, they were designed to be filled with water. However in a couple of decades time expect to find that the cylinder block and perhaps the radiator are no longer usable (the aluminium parts long before that). Once I discovered this for myself I started using a corrosion inhibitor - it's a cupful of liquid every year or two, hardly extravagant. Especially when balanced against the cost (financial and environmental) of replacing your engine and cooling system parts.

Lastly the brake fluid - if like 99% of cars in the UK it was an ethylene glycol based (DOT3 or 4) fluid, it is hygroscopic; which means it absorbs water from the atmosphere. Typically the uptake is about 1.5% by volume each year. After about the third year of service the absorption of water is enough to reduce the boiling point of the fluid to levels way below the rated specification (boiling point) of new fluid; by this time the BP of a DOT4 fluid is lower than that of new DOT3. The chemical corrosion inhibitor pack is also exhausted and your safety-critical brake components are being damaged by corrosion. All good until the split second when you need peak brake performance in an emergency and it is no longer there. If you think a pint of brake fluid is a waste, stop and think about the environmental cost of having to replace a crashed car (let's not even think about the occupants...)