torn brake caliper dust boot

[Nankumar Seewdat]

I decided to be nice and service my dads brakes on his 2010 toyota venza. Upon doing the service i realized his pads were down to almost requiring the squealer (thank god i saved his rotors). Anyways, when i went to push back the caliper to accommodate the new pads the dust boot did not compress flat, it instead bubbled a bit over (if that makes sense?) it basically was not flush with the piston. i decided to try to put it on anyways and it got caught on the brake shim and now has a very tiny rip. I was wondering if this is a serious issue and if it is hard to replace. The caliper is a dual piston set up, if that makes a difference.

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[Daniel]

I believe you have to pull the piston out to replace the boot.
If the hole isn’t that big, you could try putting some rubber cement over the hole or something, or just leave it alone.
It’s life will be shortened from the hole, but there is no way to predict when it will fail. It could go bad in 2 miles or be fine for the next 80,000.
To be clear; by “fail” I mean the piston will seize or won’t return back into it’s bore. You won’t find yourself with no brakes. So I really don’t think it is going to create an unsafe situation.

[Nankumar Seewdat]

ok well since i don’t have compressed air to remove the piston I might just leave it be. I don’t want to try to seal it up with a cement or anything mainly because i don’t want it to fall through and possibly cease the piston (unless the boot doesn’t allow access under the tear then i will try using the cement). Thanks for the quick reply, definitely relieved some stress.

[Nankumar Seewdat]

also, what could i do to prevent the dust boot from doing that again? did i do something wrong or was there something wrong with the boot?

[Daniel]

It should have been flush with the piston face.
Did any fluid come out of the tear?
What did you use to compress the piston?

[Mike]

I’ve encountered the boot bubble many times, I use a 90 degree pick and go in doing 2 things. First is that I put the end of the pick up between the caliper piston and boot and when I feel the end of the pic hit the boot, I turn the handle of the pick so it lifts the boot away from the piston and lets the trapped air out. At least half the time the bubble deflates and that part of the boot goes right back to being folded over properly the way it’s supposed to be. Sometimes I have to also use the elbow of he pick to push the boot back into place if it doesn’t deflate on it’s own and then repeat the cycle of pulling the boot away from the piston and then pushing the boot back into place.

To deal with your current problem, the good idea of using some silicone RTV to cover the hole should be done. Getting a little grease or oil of some kind in the hole to help recover the metal from any environmental damage would be useful, but the hole in the rubber where you silicone it has to be clean for the RTV to stick properly. Wiping it with a rag wet with brake-cleaner till it looks clean and dry looking does the job.

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