Caliper failure


#1

I have a 2002 Nissan Sentra - 100k miles and would like to know whether I’ve been had. I had a shop check my brakes and they reported that I had 30% left on the front brake and 50% left on the back brake, they even wrote in the comments ‘good’ and then recommended brake pad replacement in 6 months. I bought my car new 5 years ago changed only the front brake pads once. I started to hear a grinding sound about 5 months after the brake inspection and assumed it couldn’t be the brakes since they had been checked. However, 5 months after telling me everything was good for another 6 months, I paid them $1400 to replace the brakes, the rotors, and the calipers, front and rear because so they told me, my brake pads had completely worn through and I had been braking with metal on metal. The shops front desk guy explained that it was a mechanical issue with the calipers locking up and the brake pads wearing through rapidly and I couldn’t have done anything to prevent the problem. Is it likely for all 4 calipers to fail at the same time? However, as I finish paying, the mechanic who had worked on my car tells me that I should have my brakes checked annually and after I mention that I had had my brakes looked at, he responded that not everyone does a very good job and since I had uneven wearing whoever had checked my brakes may have missed the problem. Is it likely that nobody is to blame and I had a mechanical failure on all 4 calipers resulting or was I a victim of overselling?


#2

There’s not going to be enough info known to be definitive but quibbling over 1 month is a stretch.
The question that is raised for me is if you really even needed 1 caliper, much less 4 of them.

Is this one of those chain stores (Midas, Firestone, etc.)?


#3

No, not a chain store. Yeah, the real question is whether they upsold me on the calipers. They told me the brake pads wore through really fast because the calipers were stuck (not because of normal wear and tear on the brakes) and that my brake pads had baked onto the rotors.


#4

Well, the odds of having 4 calipers stick is about as likely as winning the lottery.
Normally, if one has a stuck caliper the other side is also replaced but 4 of them is grasping IMHO.

Were the pads metal on metal both on the front and rear, or rear only? If only on the rear then I would suspect a binding park brake cable.
If only on the front then it’s debateable and the true cause may never be known. Checking the calipers to see if they’re frozen is very simple but may be a moot point now.
About all I can say is that I’m extremely skeptical of the need for calipers, especially on an '02 Nissan with only a 100k miles on it.


#5

How do you check a caliper to see if it is frozen? A friend of mine may have one, the driver side front pads wore down to the metal quickly, while the passenger side front pads were still ok…


#6

If the caliper piston can be rotated and pushed back into the bore fairly easy then it should be good. On calipers with self-adjusters (usually with the park brake mechanism: rear calipers or front calipers on SAABs and early Subaru) the piston may be more difficult to rotate but the same holds true. If the piston rotates and depresses into the bore the caliper should be good.

Generally, the piston will only seize if the brake fluid is contaminated and corrosion is bad in the caliper or age has hardened the piston seal. The piston seal is square cut and relies on the distorted shape to pull the piston back off of the pads. With age the seal hardens, loses all of its spring, and may keep the piston extended (pressure on the pad).


#7

On Toyota and Honda I have noticed that it is not the piston that seizes but more often it is the sliders. Either way it is usually one caliper that seizes and you should replace the pair (although you can change only one it is not advisable). Replacing all four at once sounds like the mechanic had a boat payment due and needed to make some extra money.