See more of the story

Q: My 2014 Highlander has grease leaking from the rear liftgate power strut. Should it be replaced, and if so, how big a job is it? I try to do most work like this myself.

A: If the struts are not motorized, this is one of the easier, DIY jobs. And you can replace motorized struts with ordinary units — and save some money — if you wish. Both struts should be replaced. Just be sure to use a support such as a broomstick to hold the hatch open while you change the struts one at a time.

Helping rodents?

Q: A mouse or chipmunk ate through the windshield wiper supply hose below the reservoir container in my 2021 Honda Pilot. I firmly believe rodent damage is caused by one other thing besides cornstarch-based wiring insulation. I have seen no mention anywhere of the plastic or sometimes aluminum under-engine shields. These, I guess, are to reduce wind drag, but the handy shelves make an excellent platform or step-up location for rodents once they climb up into them. The rodent can then chew at its heart's content. Can I remove it?

A: Yes, you can remove it, but I suggest leaving it in place. If they didn't serve a purpose, carmakers would not incur the added cost of installing them. They protect the lower engine area from road debris.

Nothing to spare

Q: I am considering buying a car that instead of a spare tire has a tire sealant and inflator kit. All my previous cars have had a spare. Will a tire sealant and inflator kit work for a common flat (nail in the tire)? If so, for how long? Should I consider buying a spare and jack for peace of mind?

A: Yes, it will plug small leaks. The fix might last for a while, but you should get the tire professionally repaired or replaced. If the tire has a gash, however, there's no sealant in the universe that will work You will have to call your roadside assistance company. No need to buy a spare. Besides, where would you put it? No need to buy a jack if you don't have a spare.

Stick with air

Q: Why are new cars coming with tires filled with nitrogen? Is there any real difference from air? Also, one needs to refill them with nitrogen, but how available are nitrogen filling pumps or stations?

A: I have long contended that nitrogen for tires is a scam. The air we breathe is nearly 80% nitrogen. For as long as there have been pneumatic tires, they have been filled with plain air. Some tire dealers offer free nitrogen fills and refills for their customers, but I, for one, would never pay extra for the stuff.

Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician. His writing has appeared in automotive trade publications, Consumer Guide and Consumers Digest. Send automotive questions along with name and town to