Skip to comments.Flushing fluids isnt just unnecessary, it's potentally dangerous.
Posted on 10/04/2013 10:21:16 AM PDT by Signalman
Without trying to toot my own horn, I know a lot about cars. I understand how most items on a car function and how they fail. I know the difference between a 6 ply tire and a bias-ply tire; I can talk about the pros and cons of direct injection; I can argue in favor or against anti-lock braking systems, etc.
This knowledge frequently causes frustration when I take my vehicle in for basic services like an LOF (lube, oil, and filter), tire rotations, etc. and Im pitched an unnecessary service item. While I know the service being pitched is a giant waste of money, the average consumer probably doesnt know and that makes me angry. Service professionals who recommend unnecessary services ought to have more respect for the consumer (and better ethics).
As a general rule, fluid flushes and/or replacements are unnecessary. Heres a list of maintenance items that involve a fluid flush/replacement and guidance on whether or not to pay for each.
Power Steering Fluid Flush These are rarely if ever necessary. Power steering fluid will become dirty and smelly over time, but it will remain functional for the life of most vehicles. Unless your vehicle manufacturer recommends changing this fluid (and very few of them do), or your power steering system is giving you trouble, theres simply no reason to bother with a power steering fluid flush.
Brake Fluid Flush Brake fluid is hydrophillic, which means it sucks up water like a thirsty camel. Brake fluid can even pull water out of the humidity in the air. As brake fluid sucks up moisture, it loses effectiveness. If it absorbs enough water, brake fluid can even boil over during normal use.
In light of brake fluids sensitivity to water, automakers go to great lengths to ensure your brake system is completely and totally sealed. Therefore, the average vehicle never needs replacement brake fluid. Unless youre doing a LOT of heavy braking (racing, towing a heavy trailer on a regular basis, etc.), your brake fluid will last as long as the system remains sealed. Its almost always unnecessary to flush brake fluid.
Coolant Flush Many vehicles use long-life engine coolant, which has a typical life expectancy of 150k miles. Some still use conventional coolant, which only has a 30k mile life expectancy.
To determine if your car needs coolant flushes every 30k miles or every 150k miles, check your vehicle manufacturers scheduled maintenance booklet. Follow the interval suggested no more and no less.
Automatic Transmission Service/Flush Last but not least, automatic transmission services are often completely unnecessary. Most new vehicles use synthetic transmission fluid that can last the lifetime of the vehicle meaning that youll never, ever, EVER have to change it. Just check your vehicles maintenance booklet if you dont see a recommended transmission service interval, than your transmission doesnt need service.
NOTE: Another clue that your transmission doesnt need service? Theres no transmission fluid dipstick under the hood. Most automatic transmissions with lifetime fluid are sealed, meaning theres no way to change the fluid.
When Im told by my local shop that my transmission needs flushed, and I reply that the transmission uses a lifetime fluid, the person Im talking to will often tell me that replacing my transmission fluid couldnt hurt. This is completely and totally incorrect. Replacing the fluid on a transmission that doesnt require fluid replacement is a delicate procedure. If its done incorrectly, damage is likely.
If you take nothing else from this article, remember this: Unnecessary transmission service can cause transmission failure.
Beware Power Flushes For a time, power fluid flushes were popular. The thinking was that forcing fluid through your vehicles transmission, cooling system, etc. would be more beneficial than simply draining and replacing fluid.
Unfortunately, it took a while for auto service professionals to recognize that power flushes often do more harm than good. Power fluid flushes have caused leaks in cooling, steering, and braking systems, and theyve ruined thousands of automatic transmissions.
If your local shop wants to power flush something, find another place to get your service done. Power flushing is unnecessary, and in many cases it can cause a failure.
Although, Halogen Fluid really needs to be power flushed at least once a year.
Toyota stations are still pushing the need to clean the carbon off the throttle-plate!
At 5 years or 60k miles, some of this is required to maintain warranty. If you have a 100k warranty as I do, well....
I was advised over a decade ago against transmission flushing (by a mechanic). He said that often they clean it “too well” but did not elaborate.
I will add that the only time I have ever experienced transmission failure (on a newly purchased care under 60,000 miles) was following a transmission treatment. The car was still under warranty and the engine ran in great shape until the frame was compromised in a rear-end collision at over 100,000 miles.
Great advice - thank you!
I will follow your advice and check the manufacturer’s recommendation more carefully.
I replace the smoke on my wiring harness once every three thousand miles, and am careful to use genuige Lucas OEM smoke.
Great info, thanks for posting. I never bought the transmission fluid flush sales pitch. The first time I heard it, the guy said “...so you can see that YOUR fluid is losing its nice pinkish color.” Sheesh.
Good post. Right on the money.
This sounds like it should set off the BS meter.
Just try running that F150 for its lifetime without changing the transmission fluid. You will be replacing it at around 100k.
As the author states, most cars sold today use synthetic ATF which is far more resistant to thermal breakdown (the main cause of tranny failure) than conventional fluid. Unless, you use your vehicle for frequent towing, synthetic ATF can easily last 150K miles.
A buddy of mine had his Chrysler minivan's transmission die right after 60K. He had not changed the fluid. He's not sure if it would have made a difference. He skipped this issue for his next vehicle by buying a Honda.
Drink warm beer do ya?
I take my plasma HDTV in at least once a year to have the plasma “topped off”. Once every three years I plan to have the plasma “flushed”. /sarc
And never use that 'engine leak fixer' fluid stuff. And DO use synthetic motor oil because you can go up to 10,000 mi before an oil change!
Most IMPORTANT service for a car is to DO REGULAR OIL CHANGES (EVERY 6,000 MI (AVG.)) AND ALWAYS CHECK YOUR OIL DIPSTICK LEVEL!!!
Oh, and.. DRIVE A MANUAL TRANS., NOT AN AUTOMATIC!!! And NEVER get a BLACK car because you will have to wash it constantly and it's about 10 degrees hotter on the inside on hot days than a white car is.
How often do I need to repack muffler bearings?
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