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Missing Brake Pad

Joined
4 June 2003
Messages
961
Location
Beacon,NY
So as the title suggests my wife's minivan (a 2011 Toyota Sienna) was missing the driver's side inner brake pad. She texted me to tell me that she heard a noise and then the brakes were not as effective. When I got home the first thing I noticed was a puddle of brake fluid in the area of the driver's side front wheel. Upon further inspection I discovered that the inner brake pad was missing and the piston had popped out of the caliper spilling a good amount of brake fluid. I did not even know this was possible since the pad is pretty much locked in there. A trip to an autoparts store and I ordered a couple of new rotors, pads and the drivers side caliper. I guess the moral of the story is make sure you drive your wife's car once in a while. It must have been making some horrible noise prior to the incident. I guess it could have been much worse. Anyone seen this before??
 
Wow.
The pads are positively controlled in the caliper by the mounting bolts and the caliper. I could imagine if something got kicked up into the caliper, it could bend / tear the backing plate apart. An even less likely would be a manufacturing defect of the pad with some type of stress cracking of the backing plate to the point it failed? Or perhaps a combination of the two?
 
I guess the moral of the story is make sure you drive your wife's car once in a while

First glad no one got hurt. I drive my wife's Nissan Rogue (lease) at least once a week just to make sure everything is good. I can't trust her with an older car lol I never leased a car until I saw what she did my Audi A6, couldn't risk a big repair on that V8 motor.
 
So I've talked to a couple of people who have seen this happen before. Mostly, if not all the time, happens on the caliper side where the pistons are pushing the pad. I've since replaced the caliper, rotors, and pads. The box is back up and running and the wife is happy. Those brakes were about 30k old so I will have to make sure to check them more often.
 
So I've talked to a couple of people who have seen this happen before. Mostly, if not all the time, happens on the caliper side where the pistons are pushing the pad. I've since replaced the caliper, rotors, and pads. The box is back up and running and the wife is happy. Those brakes were about 30k old so I will have to make sure to check them more often.

What is the root cause?
 
What is the root cause?

Your guess is as good as mine. When I have driven our van in the past I did not notice any uneven braking. What was a bit unusual, in addition to the missing pad, was that the passenger side brake was still within it's serviceable limit so there was certainly some extra friction going on with the driver side brake. I've experienced a siezed caliper before and that was not happening. I'm just glad it's fixed now and it did not cost me a thousand bucks. About 200 for a new caliper, two new rotors and pads if you're wondering.
 
Just leased my wife a 2019 TLX A Spec, I make sure to snag the keys a least once a week.
 
Your guess is as good as mine. When I have driven our van in the past I did not notice any uneven braking. What was a bit unusual, in addition to the missing pad, was that the passenger side brake was still within it's serviceable limit so there was certainly some extra friction going on with the driver side brake. I've experienced a siezed caliper before and that was not happening. I'm just glad it's fixed now and it did not cost me a thousand bucks. About 200 for a new caliper, two new rotors and pads if you're wondering.

You mentioned a seized caliper, for clarity are you referring to the piston stuck in the caliper or the caliper not moving on the bracket? Many times I see this issue where the caliper is not sliding on the bracket pins, so once you brake, it keeps the pads against the rotor. I always remove the caliper pins and regrease them as part of the brake job, since I have seen this many times.

HTH,
LarryB
 
Many times I see this issue where the caliper is not sliding on the bracket pins, so once you brake, it keeps the pads against the rotor. I always remove the caliper pins and regrease them as part of the brake job, since I have seen this many times.

HTH,
LarryB

This is an issue with hybrid/electric cars that use a good deal of regenerative braking (so the pads/rotors rarely need replacing for the first 100k miles), but the caliper slide pins still need to be taken apart and lubed.

OEMs are always trying to go to more environmentally-friendly lubes, and they don't seem to be as good as or last as long as moly/PTFE mixes. If you haven't preventatively-replaced the caliper slide pin lube in your Toyota hybrid within the first 30k miles, then it is probably stuck!
 
You mentioned a seized caliper, for clarity are you referring to the piston stuck in the caliper or the caliper not moving on the bracket? Many times I see this issue where the caliper is not sliding on the bracket pins, so once you brake, it keeps the pads against the rotor. I always remove the caliper pins and regrease them as part of the brake job, since I have seen this many times.

HTH,
LarryB

Hey Larry. Thanks for the input. Hope that you're well. If I was going to bet someone I'd say you hit the nail on the head with the bracket pins not sliding freely. When I had a seized caliper in my CRX it was stuck out (the piston) and causing the rotor to get hot (red hot). Never experienced that with the van. Are you still working on NSXs?
 
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