16 years ago I bought a 1985 FJ60 with 172K on the clock. It had one frozen piston in one caliper. The snap ring on the boot was missing. That allowed crud to get in and corode the piston material which then froze in the bore. Using a HUGE amount of leverage, I removed the bolts that hold the caliper together. I removed the frozen piston, touched it up with emery cloth, reassembled the caliper and replaced the clip. Now, 16 years and 232,000 additional miles later it still works fine, no leaks, no freezing up. These are the same basic design. If the clip is missing, replace it. If it freezes and you have some dgree of technical savy, don't be afraid to try to bring it back to life. It's either you or some guy in China doing it, I know what my choice is.
Stock 4runner calipers don't have a snap ring on the piston boot. Some aftermarket replacements do.
82K both rears completely frozen, driver side front sticky and passenger side front o.k. Unfortuantely, it looks like two rotors also for good measure. Disappointed, but expected this day to come...thanks Toyota!
You're the FIRST person I heard of that has had a problem with the REAR calipers. I have over 230k miles on my rear calipers..and they are fine...The front are a different story.
Are the symptoms limited to excessive heat (hard to detect in winter) and excessive brake dust?
You're the FIRST person I heard of that has had a problem with the REAR calipers. I have over 230k miles on my rear calipers..and they are fine...The front are a different story.
You're the FIRST person I heard of that has had a problem with the REAR calipers. I have over 230k miles on my rear calipers..and they are fine...The front are a different story.
Ok, finally had to replace them again (see post #222). I had found them starting to freeze again last year and got most of the pistons working again, but now the right front was dragging badly (pads mostly worn away too) and it was time to replace. Had replaced them with NAPA units Oct/Nov 2010. I was finally able to find both receipts & took them back. NAPA repalced both for free (lifetime warranty). Neither of the old ones had the retainer clips on the dust boots; just a definate groove for the boot to sit in. The ones I just got, 1 had retainer clips (with NO groove for the dust boot) and the other didn't. I'll see if there is a marked difference in how they hold up now.
I'm also trying something new: I greased all the pistons under the dust boots. Hopefully this will help protect them from moisture. We'll see!
New pads & rotors too this time.
Also I had one of the rears freeze back in Nov 2010 after I had done the fronts, other is still fine.