The Leaky Wheel
Q: I bought a '95 Dodge Dakota pickup from a used-car lot. It came with some decent-looking mags, but I don't know what kind they are. I'm not sure if they're aftermarket or factory ones. That doesn't matter, because I'm saving my money for some 18s, or maybe even a set of 20s. Until that time, these wheels will have to do.

My problem is that two of them seem to have a problem holding air. One loses about 10 psi a week, and the other is more like 5 psi. I had the tires checked at a tire store and the guys there said the tires were fine and that the problem was probably the wheels. The store wanted to sell me new wheels, but I still need to wait.

I keep close tabs on the air pressures, but I'd like to fix the problem if it isn't too difficult or too expensive. The tire shop guys didn't offer any repairs, because they seemed more interested in selling me some new rims. Would a can of instant tire sealer fix the problem?
Darrell Yee, Ottumwa, Iowa

A: It sounds like you have a pair of overly porous alloy wheels. This is a common problem with many older factory and aftermarket alloy wheels. The instant tire sealer won't help, because it's designed to coat the inside of the rubber to stop leaks in the tire.

The first thing you need to determine is where the air is escaping. You'll need a cooperative tire repair shop to find the leak, unless you live on a farm with big water troughs.

Remove the wheel/tire combo and inflate it to 40-45 psi. Immerse the unit in a big tub of water and watch for bubbles. Use a grease pencil to mark sections of the wheel where air is escaping.

Dismount the rim. Look at the inside of the rim near the grease marks. It's likely that you won't be able to see any obvious holes. Without removing the grease reference marks, clean the inside of the rim with soap and water. Dry the wheel and then use an aerosol cleaner such as brake or carb cleaner (lacquer thinner on a rag will also work) to super-clean the area.

Cover the suspected porous area with a high-quality silicone sealer. Apply a layer of silicone approximately 1/8-inch thick. Let it cure according to the instructions. Then have the tire remounted on the rim. If the tire and rim were indexed before being separated, you probably won't need to rebalance. Check the wheel/tire combo in the water tank and hopefully there won't be any bubbles. Then work overtime so you can get the new rims.

Milky Way
Q: We had a lot of rain recently and some minor flooding. My '00 Dodge Durango ended up in a situation for a couple hours with standing water up to the axles, and possibly a little higher. I don't think the axles were submerged for any length of time, if at all.

I have access to a hoist, so just to be safe, I put the Durango up and checked the gear lube. I was dismayed to see a milky-looking lube. I changed the lube.

My concern is that I should do something to super-seal the axle. I do my best to avoid deep water, but since we live in a flood plain by a river that overflows its banks almost every year, I need to be prepared. Can you offer suggestions for waterproofing my Durango? I appreciate your help.
Ted Moultray, Carnation, Washington

A: We don't think you had water in your axles. Milky-appearing axle lube has appeared in enough '99-'00 Dodge Ram pickups, Dakota pickups, and Durangos that a technical service bulletin (TSB 03-02-00) was issued on the problem.

What happened is that some axles were assembled with a white gear-marking compound. The compound is used to check for proper alignment of the ring gear with the pinion. The white compound mixes with the normal gear lube, giving the appearance of water contamination. It isn't anything to worry about, but we'd still suggest moving to higher ground when the river rises.

Carbon Copy
Q: Is there an easy way to paint metal surfaces to look like carbon fiber? I built a custom metal console and some big speaker boxes for my tricked-out '02 Chevy Astro van. I'd like to make these items look like they're made out of carbon fiber. I've seen this on other trucks at shows, but I couldn't find anyone to tell me how it's done. Can you tell me? Thanks.
Jeremy Tretheway, San Jose, California

A: We've seen a pretty realistic rendition of faux carbon fiber done using drywall seam tape. This woven tape (usually plastic-based) is available at hardware stores and home-improvement centers. Be sure to get the woven type, not the solid-paper "tape."

Start by spraying a base color. You might want to use a color that complements the rest of the interior. Or, you could use silver for a traditional carbon-fiber look. After the base color has dried, cover the area with the drywall tape. Then spray the top or primary color. This top color can also complement the interior or it could be a dark gray or black for a standard carbon-fiber look.

When the tape is removed, you will see a "grid" or "fibers" from the base color. You can make the surface look more three-dimensional by shading the edges with the darker of the two colors. An airbrush works well for shading. You should protect the "carbon fiber" with a clearcoat. If you notice, the carbon-fiber trim in late-model cars has a glossy look to it. The clear will have to be color-sanded and buffed.

Painting faux carbon fiber is more art than science, so you might want to practice on an inexpensive blank metal sign. Any clean and prepped sheetmetal will work. Besides mastering the general technique, this is also a good way to experiment with different color combinations.