Last week when changing pads and rotors I saw that one of the accordian seals on a front caliper piston was torn. No leakage of fluid or funny stuff that I could see.

Would I be stupid to just change that dust seal?

Dave

 

I would go ahead and just rebuild the caliper. Those dust seals are a pain to get on there with the little ring that holds them in place. Most likely you'll need to pull the caliper off to get that ring on there in which I would just do a caliper rebuild.

 

The dust seal does precisely what the name suggests. It is not there to retain fluid. An indication of fluid under the seal does indicate a piston seal is defective. If the seal is torn from old age it is wise to rebuild/replace the caliper. Don't forget to flush the brake system, and check the hoses.

 

Yeah, I'm planning to rebuild the caliper.

I was just trying to get a feel for how likely the actual piston seal is to leak if the dust seal was exposed for a while.

Dave

 

You will eventually get enough moisture and durt in the piston wall to score the the surfaces. Sometimes enough scoring to not be able to hone out, and eventually leak fluid..