2002 Honda CR-V Brake Calipers

I recently had to replace a rear brake caliper because it locked and
wore the pads and then proceded to cause the rotor to be destroyed.

I am wondering if anyone else has had a problem with the brake calipers
locking up like this. The people taking care of the repairs could not
provide a real good explanation of why this would happen and actually
seem mystified by the failure.


I myself am a bit confused. I was in for services 2000 miles ago and
had my state safety inspection performed. They have never been shy
about trying to sell me repairs, so I imagine if it was something
foreseeable they would have tried to push it then; however, the only
problem they mentioned was that I would need new front brakes in the
next 5000 to 7000 miles.

So, I have a few questions:

1) Has anyone else had mysterious/unexplained caliper failures that
resulted in serious damage to their brakes?

2) What causes can cause a caliper failure? How can you prevent these
causes from resulting in failures?

3) Is there anyway to detect a failure before it wears the pad out and
starts grinding the rotor? (I never heard the wear indicators.)


I thank everyone for their help and knowledge in advance. My car
knowledge is limited to the basic tasks (i.e. changing oil, replacing
fluids, etc.)

-J

 

wrote in

Oh yes. But it's neither unexplained nor mysterious. Rotor damage is
ordinarily accompanied by a loud grinding noise, which must be ignored by
the driver in order for damage to occur. Sometimes the rotor can be damaged
by excessive heat, which warps the rotor and sometimes blues it up.

Caliper failure normally consists of the piston binding in its bore. This
is inevitable and will eventually happen to all cars. Failure to change the
brake fluid annually will hasten it.

When binding happens, the piston fails to retract immediately when you let
off the brake pedal, so the pads are under pressure for an extended length
of time (it's called "dragging"). The pads therefore wear much more
rapidly.

Binding pistons are _usually_ due to gum and/or corrosion on the piston.
Binding is something a tech really should check for when doing the brakes,
but in practice few do since it takes some time. You raise the car just off
the ground, step on the foot brake a couple of times, spin each wheel by
hand, and note any differences in turning effort. You can then back this up
with a visual inspection of the brakes.

There are services that may be performed to make certain the piston is as
free as possible. They involve silicone grease, a blunt syringe, a set of
Channel-Locks, and time.

Other failures can occur when the moisture seal fails for the parking brake
linkage inside the caliper. When it fails, moisture gets inside and
interferes with the mechanism, which may fail or stick in the "on"
position. I don't know if your car has a separate parking brake mechanism
or not.

Other problems that can lead to abnormal pad wear and damage but are not
"failures" per se: Pads seized to mount bracket; slider pins seized in
bores.

Regular servicing, or at least inspection, at least twice per year if you
live in an area with snow, and once per year in an area without.

The wear indicators are only on the inner pads. The outer pads have
nothing. Here is a hypothetical but quite possible scenario: Inner pad
seizer on its bracket. Caliper piston seizing. Slider pins free. Outer pad
does nearly 100% of work, wears out in jig time. Grinding moise evident.
Rotor damaged.