Dear Car Fix: My Honda Accord maintenance schedule didn't include specific mileages for flushing the radiator and transmission fluids. Does this mean that we should service them when an inspection shows the fluid is dirty? Or is it better to do it at specific intervals? I appreciate your advice.
-- Sincerely, A.M., Buffalo
Dear A.M.: When it comes to checking coolant/antifreeze, the best way to know when it needs to be changed is by using a hydrometer. This tool is simple to use and you can access the coolant through the radiator cap (ONLY WHEN THE ENGINE IS COLD TO AVOID A SERIOUS BURN) or in the overflow tank. There are a few different choices at your local parts store. The type with a bulb at the end looks like a turkey baster and you draw up the fluid and the gauge in the tool will tell you if the coolant still is functioning at the proper level. Or you can use a dipstick with a sensor, sort of the same way you check if you have hard water. Either way, what that status reads is important. Coolant or radiator fluid is designed to keep the engine cool in summer, warm in winter and also has rust inhibitors in the fluid. If the quality of the fluid is degraded, then it will need to be flushed and refilled. Again there are a few options here. You can do it yourself if you have the correct tools and a flush-and-fill kit. I'd recommend long-life coolant to keep the changes to a minimum. If you use traditional coolant, the green fluid, then it should be checked every six months and replaced every other year. If you fail to replace the coolant when it's used up, it will rot the water pump and internal engine components of the engine and cooling lines, which will leave an expensive repair bill.
When it comes to using the correct fluid, there are many different colors and types. GM and some of the German brands require that you utilize their special fluid. If you go to any parts store, they can guide you to the correct fluid. If you go to an independent repair shop, they will know the proper fluid. I'd request the long-life fluid although it may be a touch more expensive than the regular coolant; it is the best choice for any car. Another great reason to go to an independent repair shop is that they will most likely run a pressure check on your coolant system to check for leaks. You don't have to go to the dealer as any ASE-certified technician can change your coolant at a reasonable price.
As for transmissions, some cars have sealed transmissions and won't need to be serviced until about 100,000 miles (that's what the manufacturers say anyway). If you have a regular automatic transmission, then you need to check the levels every six months, and as long as you are not having a problem, you can have the filter and fluid changed based on your usage. This is tricky because if you tow a trailer, sit in stop-and-go traffic or you have high mileage, the fluid may need to be replaced at 30,000 miles. If you are unsure, have the fluid checked when you do your regular service intervals. Of course, if the shifting is rough or there is a problem, check with an independent repair shop or transmission shop to get the problem fixed quickly.
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Dear Car Fix: I just traded in my 2005 Subaru Imprezza WRX for a 2011 Imprezza WRX. The 2011 has 17-inch wheels. I have a set of snow tires on the 16-inch wheels that the 2005 took. Someone told me that you can sometimes use snow tires an inch smaller than the original ones. I'm trying to prepare in advance for the cooler weather. Is this true or do I have to buy new snows and wheels for next winter? Thanks.
-- B.M., Snyder
Dear B.M.: When replacing tires for summer or winter, always make sure that the outside diameter is the same, as it will cause your odometer, speedometer and speed sensors to read incorrectly. This can affect your Antilock Braking System, traction control and other sensors, too.
The best way to find the correct tires is to check with a local tire store, and they can guide you with the right tires as well as good, better or best options based on your driving needs. You will need to bring them the winter tire size as well as the rim width. In addition, when you go to a smaller rim, there may be clearance issues with brake calipers, rotors or wheel housings.
If you are unsure, you can also check www.TireRack.com, which posts sizing information on the website. If you do need new rims and winter tires, there are package deals available. Make sure to price it locally as well, as many shops will match the prices and save you on the freight.