Fluid Flush Fallacy[/align]Just a 'Nightline' Away From Scandal[/align]By DOUGLAS FLINT AOL Auto Section[/align]

If you take your car to a shop for a routine oil change you have a high probability of being told your car needs one or more of its critical fluids flushed, changed or serviced. This started originally at the quick-lube shops and spread to the whole auto repair industry, including the dealers.

Part of the reason is technology. New machines have made it possible in most cases to change the fluids quickly and easily, or so the sellers of the machines say. But the real driving force is profitability.

Today I'm changing a timing belt and water pump on a Dodge Caravan. It will take all of five hours of bay time, a lot of parts and a lot of potential liability. In half the time I could do a series of flushes with little effort or liability and make much more profit. Since most people, mechanics and shop owners included, respond to economic incentives, it is coming to pass that every car going to every shop needs every fluid flushed every day.

In short, what is really being flushed is your wallet. It is straining the credibility of an industry that rightly or wrongly has always had credibility problems.

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[ul]The Four Flushes
Old-timers from the '50s, '60s and '70s always knew it was a good idea to periodically drain the radiator, put a bottle of flush chemical and water in, run it a half-hour then wash it out again with plain water before refilling it with the proper mix of antifreeze and distilled water. Or if you wanted to do a really nice job you could cut one of those plastic flush tees from a Prestone flush kit into the heater hose, allowing you to hook a garden hose up and run a continuous flush.

Now these old-timers are being told their transmission fluid, power steering fluid, and who knows what else must be flushed on a yearly, monthly, or even daily regimen. Strangely, their '77 Olds Cutlass managed to run 180,000 miles without all this attention.

Now don't get me wrong. I am in favor of changing most fluids at 30, 60, and 90,000-mile intervals, regardless of what the owner's manual says. But that is not what's happening. These services are being oversold to a degree that is bound to damage the reputation of our industry to the net result that consumers will not believe any of us, even when we are telling the truth.

The Rundown
Let's start with the automatic transmission -- the most frequently flushed fluid besides the radiator. The advent of the transmission fluid exchange machine was a great step. In the past, automatic transmission fluid could only be changed by removing the transmission oil pan, which only holds three to six of the eight to 10 quarts in the transmission. The second you started the car, the new fluid mixed with the old, eliminating much of the benefit of the service.

The fluid exchange machine, which some people choose to call a flush machine, cuts into the transmission cooler line at the radiator. As the car runs, old fluid goes out into the waste tank while new fluid is simultaneously pumped in. If the shop is really thorough, the car is lifted and actually driven through all the gears while the exchange is taking place. And if the service is done properly, the transmission oil pan still has to be removed and cleaned and the filter replaced -- a solid hour and a half of work. So if a quick-lube shop is offering it to you in 35 minutes, something's not being done.

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Now, as to checking the dipstick for color or smell to determine if your fluid needs to be changed: At the extremes (not changed for 100,000 miles or changed yesterday), you can tell. But as far as whether it was changed 3,000 miles ago or 20,000 miles ago, no one can know, and if

 

pretty good information should be a good read for those new to the car world

 

thanks for providing that info to all of us old and new

 

I knew I guy with an 80's Cutlass that needed to change his blinker fluid in his tail lights all the time. I finally recommended to drill a small whole in the bottom of each on to let the rain out that kept leaking in.

The tail lights would fill a full 4 inches... just shy of seeping into the electronics. =P

 

I flush my windshield washer fluid every 6 months. You don't want that stuff getting old.

 

Hey Space,

Great post, very informative, I forwarded this on to my g/f who seems to be prone to these selling techniques. My question to you is this. At what mileage do you recommend changing what fluids??

 

i think most owners manuals have a scheduled maintence list, but then the intervals might be a bit more often than neccesary to cover thier butts