Q Since it's been cold, I've had difficulty pushing in the button on the shift lever on my 1996 Jeep Grand Cherokee. The Jeep starts fine, but I have to sit for at least four minutes before I can get that button pushed in. I'm concerned that someday I won't be able to get it pushed in at all -- and I'll be stuck somewhere. Any thoughts?

A Maybe finger curls to strengthen you fingers? According to my Alldata automotive database, "shifting out of park should not be possible while applying 25 lb. max. handle push-button force, and ignition key cylinder is in the run or start positions, unless the foot brake pedal is depressed approximately 1/2 inch." So you must push firmly on the brake pedal with the ignition on to allow the shift mechanism to shift out of park.

Try a spritz of aerosol lubricant around the button to help flush any grease, debris or soda-pop residue out of the button assembly. You might also have to remove the shift console cover to clean and lubricate the shift interlock cable assembly.

The problem could also be binding in the cable itself or the interlock cable cam and slider at the ignition switch. Try turning the key to the "on" position without starting the vehicle, push the brake pedal firmly, and while trying to push in the shift-lever button, wiggle the ignition key around in the "on" position to see if the slider releases the cam and cable. If so, this is the area that needs cleaning and lubrication.

Q We bought a used 2003 Tiffin Phaeton 40-foot class A motor home in August 2009. I check and top off the batteries as needed every month. When I checked the four 6-volt house batteries this month, I found three of them were good, but the fourth battery was completely dry and left acid stains on the concrete under the RV. RV dealers advise me that if I install just one battery, the other three will drag it down to their lowest level, so I should replace all four. These are costly golf-cart batteries. Should I replace just one or should I replace all four?

A I'm sure the "correct" answer is to replace all four. However, being a founding member of the "snug club," I would replace the one failed battery with a good used battery. In my efforts to extend the life of the batteries in my golf cart, I've bought and installed a good used battery on two occasions. Check with local golf cart dealers. I was able to buy the used batteries for $20 to $25 each. So far, my under $50 investment -- instead of $500-plus investment for a complete new set of six batteries -- has bought me an extra year of service, although I suspect I'll have to replace the entire set sometime this year.

Q I have a 2004 Kia Sorento with 60,000 miles. I can't seem to keep coolant in it. A couple of times the fluid came out onto the ground. I've had the thermostat replaced twice. I was told it may be the head gasket. I just filled it again today and it took almost a gallon. Where is it going?

A The simple answer would be a faulty pressure cap failing to hold pressure and allowing excess coolant to escape. A more troublesome answer would be a failed intake manifold gasket or cylinder head gasket. Try a new pressure cap first, but if that doesn't solve the problem, have the coolant tested for the presence of exhaust hydrocarbons -- a clear sign of head-gasket failure.