Drive it forever: Keep your fancy wheels waxed

Dear Mike: My wife has a 3-year-old Volvo XC70. We love the car — with one exception. In muddy or snowy conditions debris gathers in the rim; the wheels then become unstable and the car develops a vibration. It feels similar to a wheel going off-balance.

I have called two different Volvo dealerships and have been told the same thing — that this is normal for low-profile tires. I have, however, ridden in several vehicles with low-profile tires and have never experienced this problem. I heard from someone at the dealership shortly after we bought the vehicle that this was a defect in the rims.

I would really like to know what to do. It is a big problem — the car rarely drives as smoothly as a car of this stature should. I would appreciate your help and advice. Thanks.

— M.T., Lake Orion, Mich.

A: Yup, some of those fancy alloy wheels are prone to collecting mud or snow. I’ve driven cars that were so bad that I had to stop every 20 miles and clean the snow from the rims with my hands. My only suggestion is to keep them very clean and waxed so that the mud and snow don’t stick as easily. That will help, but it won’t eliminate the problem.

Dear Mike: My 2000 two-wheel-drive Ford Expedition’s rear brake drum/rotor is rusted fast to the axle. It has a tight slip fit to the axle boss. I have put penetrating oil on this joint, and subjected it to torsion and light hammer blows and wedges driven between the rotor/disc and the caliper mount, to no avail. I also have driven the car with the lug nuts very lightly tightened and made hard stops going backward and forward at low speeds. The parking brake was adjusted to pull the shoe assembly away from the drum.

How do I separate them?

A: Brake parts that have become one with the hub can be mighty stubborn. And whanging on them with a big hammer is more than likely to warp them because that drum is made of old-fashioned cast iron.

Start with more penetrating oil and some moderate hammer taps. The tapping will break up the crystalline structure of the rust that has locked up the joint. After this has failed to work, apply heat. A propane torch — or better yet, two — will make the drum expand ever so slightly, at which time the penetrating-oil-and-tapping routine may work.

Or not. In that case, you’ll need to rent or borrow a brake-drum puller. This device has arms to hook over the edge of the drum and a large-diameter screw in the center that will pull the drum off anything. It also has enough starch to bend the drum as if it were a Frisbee pounced on by an Irish setter, so be prepared to replace the drum after you pry it off.

Prevent this problem by cleaning the mating surfaces of the new drum and the axle with a wire brush. Then smear the surfaces with a thin coating of — what else? — anti-seize compound. Actually, high-temperature brake-caliper grease is almost as good.

Dear Mike: I have a friend who tells me that if I install mud flaps on my car, it will increase the drag. How much, if any, do these additions affect gas mileage?

— W.A.W., Sr.

A: Yes, they’ll increase drag and consequently increase fuel consumption. But I don’t think it will be noticeable.

Dear Mike: My 2005 Toyota Avalon Limited manual directs me to use 91 octane fuel. It is not available in this area of Long Island. Can I mix 87 octane with 93 octane or 89 octane with 93 octane to meet the manufacturer’s recommendation?

— S.

A: Yes.

Dear Mike: Can G-05 antifreeze be mixed with Prestone’s green antifreeze or another green-colored antifreeze?

A: No. As a general rule, don’t mix antifreeze types. I would never use anything except the same brand and type at any one time, and that includes just topping off a low system. The additive packages use different chemistry, and mixing them will upset the balance.