How fast do brake pads wear out?

cmwoodsie72

I just drove from San Diego to Baltimore, almost 3,000 miles. Before leaving San Diego, I took my car to my trusted mechanics and asked them to check it over for a road trip. They took the wheels off and looked at the brake pads, and said that all four were between 8-12mm. I drove across the country, most of the time on cruise, not braking particularly hard or frequently, even when coming down off the mountains.

I took the car in to a shop upon arriving in Baltimore for a state-mandated inspection, about 2 weeks since the initial pre-road trip check. They said my front brake pads were at 2mm!!! I paid to have them replaced, of course. Unfortunately, I don't have the info handy to say when the pads were last replaced, but I think it was about 2-3 years ago.

My questions are: do brake pads wear down THAT quickly? Does long-distance driving wear them down excessively, despite infrequent braking? Is the most likely explanation that the pre-road trip assessment was way off?

waterboy

That amount of wear would be unusual.

UncleTurbo

A 3,000 mile road trip on mainly expressways would have minimal wear on your brake pads. Now if you were towing a trailer and did a lot of braking in the mountains, that might wear the pads faster. Otherwise, no the trip didn't wear out the pads. Either the shop prior to the trip was wrong, the shop at the end of the trip was wrong, you have 4 sticky brake calipers, or you rode across the country with you left foot resting lightly on the brake petal. Choose the one that makes the most sense to you.

If you brake with the same foot as you use on the gas petal, you didn't have a foot on the brake petal. 4 stickly calipers is not likely at all. The shop at the start of the trip had nothing to gain by telling you the brake pads were good for the trip. The shop at the end of the trip did get you to put on new pads, did they show you the old pads? If yes, are you sure these were the pads from your car? Not substitutes for the purpose of selling a brake job? I don't trust the shop the did the brake job, but not much you can do about it now.

circuitsmith

I've long suspected Maryland's car inspection system is inherently corrupt.
After all the same guy who inspects your car (for a fee) can repair it.
I've dealt with this system a number of times and I've never seen a used car pass without an additional vig (loan shark term for exorbitant interest payment).

The upside is you only have to go through this once for as long as you own the car in MD.

Goldwing

Did you ask for the old pads or see that they were actually at 2 mm? They didn't wear much at all on the trip.

benabeyta

Driving from San Diego to Baltimore usually entails a trip through the Rockies. I've seen many people who use up more of thier brake pads going once through the Rocky Mountains than they normally would in a year of driving. However, I have noticed that pads typically last more than 2-3 years. I think you may have purchased an inferior brand of brake pad at the last change out. Also, if your rear pads are not at 2 mm yet, it's quite normal for the front pads to wear more than the rear since most cars get 80% of thier braking power from the front brakes. what I think happened is that you used more braking through Rockies, and where even I tend to ride the brakes even on the interstates, and a combination of cheaper brake pads. I really don't think that the mechanic in Baltimore is going to claim something that cheap to fix and have it be a scam.

benabeyta

Also, actually, come to think of it, there are as many as 3 mountain ranges that you possibly had to drive through. That can mean quite a bit of extra braking, even on the interstates.

ok4450

The mountain driving could certainly do it. A lady friend of my wife and her husband went to Colorado for a few days and their brakes were flat gone after being up there about 2 days. The vehicle had been looked over before they left on the trip and they were fine then.
The final run down Pike's Peak is what apparently finished them off. (Jeep Cherokee is the vehicle in this case.)

cmwoodsie72

Thanks for all the comments, friends! No, I didn't think to ask the Maryland shop if I could see the brake pads. Next time... They agreed to pass my car inspection but strongly urged me to get them replaced within the next 3K miles. They didn't push me to have the repair done at their shop. My gut feeling is that these fellows were legit, but I thought I'd ask just in case. To pass inspection I only had to replace the very worn-out windshield wipers. Okay, now that y'all mention it, I did indeed traverse three mountain ranges: a smaller range in southern California, the Rockies and the Appalachian ranges. It's quite possible that my brake pads were of the cheap variety, like was hypothesized. I didn't ride the brake petal; in fact, much of the time I sat cross-legged, when there were no other vehicles around. Not sure if my brake calipers were sticky, but the fact that only the front brake pads needed replacing makes me guess that either the pre-trip shop was incorrect, or I really did wear them out during the trip. Thanks, y'all!!!! :D

ok4450

The front brakes do about 70% of the braking (possibly more factoring in downgrade braking) so the fronts will generally wear much faster than the rears.

Bing

They have lasted me anywhere from 15K to 80K depending upon the type of driving done. So either the first guy was mistaken, you rode the brakes through the mountains, or the second guy was scamming. The easiest way was to just go look at the pads before they replaced them when the wheel was off, or simply ask for the old pads back.