When you isolate the caliper and touch it, it’s surprisingly “hard to feel the piston operation” .
The piston operation is “stiff, so you need to work it out carefully” . It takes quite a bit of time.
It improves “at first” , but after covering some distance “the same situation returns” . . . .
“Seal degradation (rubber) and debris accumulation in the seal groove” are the main causes, so
The caliper piston can “be retracted without much force if in normal condition” .
Of course,
straight “without tilting” is the prerequisite for retracting it.
If you can’t retract it without tools… that’s likely already due to seal degradation and debris accumulation.
“Do you need to wash and work it out?”
This is “maintenance work that’s useful when the brake caliper is healthy” .
It’s not “work to fix something in bad condition” , so make no mistake…
However, “there is some improvement” , so deciding based on the situation is the trickiest part.
An OH is “the most effective and cleanest” result
“Hardened and deformed seals get refreshed” .
Since the caliper is isolated, “you can clean it thoroughly to the deepest parts” .
Working one caliper for an hour? or something like that…
“Takes time with thin results and poor durability” .
Spending the same time on “an OH would definitely be more effective” .
One more time to wrap up
“Seal degradation (rubber) and
debris accumulation in the seal groove” are the main causes
Working it out won’t refresh the rubber…. and working it out won’t remove the debris.
