Drive it forever : Your rear brakes need attention
Dear Mike: I purchased a new Olds Intrigue in September 1998. The left rear brake rotor had a visible rust scale ring around the exterior about one-quarter-inch wide, roughly in the center of the swept area. I figured it would be worn away with brake usage. After 98,000 miles on the vehicle, it hasn’t gone away. The rear rotors are not even shiny and the original rear brake pads show very little wear. My wife and I are not very hard on brakes; we replaced the front pads for the first time at 86,000 miles.
Is there a proportioning valve between the front and rear systems that should be replaced?
A: Obviously, the rear brakes on your Olds aren’t doing their share of the work or the rear discs would be as shiny and rust-free as the fronts. The proportioning between the front and rear brakes is achieved by the varying diameters of the pistons in the respective calipers, and (in some vehicles) by a separate proportioning valve. Other vehicles also use a check valve that maintains a minimum pressure in the rear brake lines to reduce pedal travel.
If there isn’t a pound or two of residual pressure in the lines, the rear pads will work their way back into the calipers a few thousandths of an inch because of brake disc run-out, which is normal. If so, most of your initial brake pedal travel just gets the pads back to where they belong. The check valves in your car are inside the master cylinder. You car has enough mileage on it to justify replacing the entire master cylinder.
Dear Mike: I have a ‘97 Cadillac STS, 172,850 miles, with a slow oil leak. The mechanic at the dealership says it is a high-pressure leak as it is not noticeable. But I lose about a quart of oil every 3,000 miles to 4,000 miles. The mechanic tells my wife that he needs to fix this before the engine blows up.
A: Keep that mechanic away from your wife. There are no slow high-pressure leaks. Losing one quart every 3,000 miles to 4,000 miles isn’t much of a leak. In fact, that’s in the category of normal oil consumption, especially for a vehicle well into its second centennial. When the mechanic says it is not noticeable, does he mean that it isn’t making a puddle under the car? If so, just drive the car, check the oil every thousand miles or so, and stop worrying.
Dear Mike: I have a 2000 Mitsubishi Galant ES, and my dealership mechanic told me I need to replace the timing belt ASAP, especially since I live in Florida and it may be cracking due to the hot weather — even though I only have 30,000 miles on the car. The mechanic says he’ll give me a discount price of $400 including labor, etc. Do I need to do this right now, and is the price in the correct range for this type of work? Can he check the belt to see if it is cracked or not before I commit to doing the work?
A: The price you’ve been quoted is pretty much on target. But I wouldn’t be in a hurry to replace it before Mitsubishi’s recommended interval.
Dear Mike: Like many people interested in keeping their vehicle a long time, I liked to use synthetic oil from the start. But with the high cost I would like to take advantage of synthetic’s long life and only change the oil once a year. But this would void my warranty.
Is it worth switching to synthetic after several years with petroleum-based oil? Why haven’t car manufacturers come into the 21st century in regards to using synthetic?
A: Several car manufacturers have already switched to synthetics for factory fill. But although synthetics are superior, they still need regular changing. It is not a good place to save money.
Dear Mike: I have a 1985 Evinrude outboard engine and I’m wondering what affect fuel with ethanol will have, if any, on its performance or maintenance issues.
A: A small percentage of ethanol won’t have much affect. More will make the engine run lean — and two-strokes are not very tolerant of running lean. So stick with fuel that is less then 10 percent alcohol. And don’t overdo the oil in the gas — this also makes the engine run leaner. Use the manufacturer’s recommended fuel mix.