Sunday, July 5, 2009
Dear Tom and Ray:
Last week, I was cleaning the interior of my '04 Ford Escape. To reach a part of the console between the two front seats, I had to raise the emergency-brake lever. Stupidly, I forgot that I had done so, and drove the car about five miles. How much damage did I do to my brake linings? I must not have had the emergency brake fully engaged, because I was not aware of any braking sensation as I was driving. -- Jim
TOM: You probably did no damage at all, Jim. You must have had the parking brake loosely applied. If it had been really engaged, one of two things would have happened:
RAY: One, you would have felt resistance when you tried to drive. It would have felt like . . . well, like the brakes were on. Or two, you would have smelled the brakes burning after a mile or two. And you noticed neither.
TOM: I guess you didn't notice the big, red light on the dashboard that said "Brake!" either, huh?
RAY: My guess is that, in five miles with the brake loosely applied, you hardly did anything. You wore a little bit of surface off the parking-brake drum. On this car, it's a separate unit from the regular brakes, so it would have no effect on normal stopping.
TOM: To give yourself peace of mind, next time you're on a hill, put the car in neutral and apply the parking brake so it's fully on. Then see if the car rolls. If it does, you can ask your dealer to have a look. If not, forget all about it.
Dear Tom and Ray:
My father taught me a lot about cars by having me do the work while he "supervised." I don't remember how old I was, maybe 8 or 10, but I was young enough that I had to stand on a crate to reach over the hood to the engine. The lesson of the day was how to change spark plugs in the old family Chevy. I was determined to show my dad how "big and strong" I was, so I cranked on the plug probably more than he thought I could at my young age. As he was standing there smoking his pipe and watching, I snapped that baby off in the block. He never yelled, just kept looking at the engine, and finally said, "Run in and tell your mother we'll be a little late for dinner." That started the next lesson, on how to use a torque wrench (he spared me the task of extracting the old plug and fixing what I had done). I am now 53 years old, my dad is long gone, and I still have the torque wrenches of my dad's that I made sure I got when he passed. Can I still trust them? Is there any way to check or calibrate them? -- Jim
TOM: Your dad sounds like a wonderful, patient man, Jim.
RAY: You have two different types of torque wrenches, Jim. The old "bar and pointer" type were never extremely accurate. But the good news is that they almost never went out of calibration from where they started. And they're good enough for most automotive work. So I think you can continue to use those for things like spark plugs and wheel nuts. The "click" type are more accurate, but they can go out of calibration over time. Those should be recalibrated if you're doing any kind of precise work.
TOM: If you go online and search on Google for "torque wrench calibration," you'll find a number of labs where you can send your wrenches. They'll recalibrate them and send them back to you.
RAY: There are even some that will come to your house or place of business and do the calibration on the spot. And since your wrenches are irreplaceable and have great sentimental value, you might want to do that, rather than take the chance of having them get lost in transit somewhere.
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Copyright 2007 by Tom and Ray Magliozzi and Doug Berman