Car Doctor: Why do the brakes on my CX-5 make noise when I shift into reverse?

·3 min read

Q: The brakes on my Mazda CX-5 make a noise only when I shift to reverse. What can the problem be? What would be a low-cost way to resolve this?

A: The very first thing you should do is to have the brakes inspected to ensure there are no serious problems. If the brake pads and calipers look OK, there are a few possible causes of this noise.

On some models there is a special grease between the brake pad and pad shim. Over time, the grease deteriorates and allows the pads to vibrate and cause a noise.

The second issue is due to the brake pad design; rust builds up on the rotors and causes a noise as it wears away.

The third possibility is you are hearing the electronic parking brake release.

These three issues are fairly minor — although annoying — but the brake system should be inspected to rule out serious and potentially dangerous problems.

Q: Six years ago, I decided to get a riding lawn mower. I have heard you extol the benefits of synthetic motor oil and decided to use that in the lawn tractor. I realize you are a proponent of doing oil changes annually regardless of the mileage (or time).

After six years of use, there is only 120 hours on the meter, so my annual usage amounts to 20 hours per year. Can I change the oil on a every-other-year basis, or is that just being "penny-wise and pound foolish"?

A: Annual oil changes are important, since the oil can pick up moisture and contamination from unburned fuel.

In what may be the dumbest thing ever, I recently purchased a little boat. The factory manual states that the oil should be changed every 100 hours, or yearly.

I will only have about 30 hours on it when it gets put away, but I will change the oil, just to be safe and protect my investment. That would also be my suggestion for your tractor: Change the oil at the end of the mowing season.

Q: I have a 2021 Honda Ridgeline RTL-E. The issue is the front heat/AC vent that is located directly above the start button and the one to the right of the radio. Even when I don’t have heat turned on, there is heat coming out of these two vents.

Why Honda has controls too close to these vents is beyond me. I hate having hot air blow in my face. When I turn the heat on and tell the system to blow only downward on my feet/legs, it still comes out of the front vents.

I've been to two dealerships, and they say this is normal in all cars. I asked them then why this doesn't happen in my other car, a 2019 Chrysler 300. They could not answer me, since it is not a Honda.

Is this normal, or should I be more adamant with Honda?

A: This design could be part of the air flow system to keep cabin air circulating.

The easiest way to check this is to drive another Honda Ridgeline and see if it acts in the same manner. If it does, it is a characteristic of the climate-control system. Perhaps it's not a desirable characteristic, but it's something that can’t be changed.

If the comparable vehicle shuts off the air flow to those vents, your vehicle has an issue, and the dealer should be able to resolve it.

AAA's Car Doctor, John Paul
AAA's Car Doctor, John Paul

Q: I recently replaced the windshield wipers on my car, and they chatter. I went back to the store and purchased a new set and they still chatter. Why?

A: The issue is that the wiper arms have probably distorted over time, and the wiper blade edge is no longer perpendicular to the windshield.

In most cases, using an adjustable wrench on the wiper arm and tweaking the angle a bit is enough to eliminate the chatter.

John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.

This article originally appeared on The Providence Journal: Why do brakes on my CX-5 make noise shifting to reverse?