newbster
Registered User
just had to replace a rear caliper because the handbrake was sticking on, also chewed up the disc and pad.
I'm a little ocd on finding out how thing work and why they failed
anyways, the new caliper was a non exchange unit, so thought i's try and pull the old one apart.
not too difficult really.
the lever that the cable hooks into is connected to the shaft at the left end, where my finger is.
shaft rotates, and the plate stays still, there are 3 ball bearings between the two parts, sitting in ramps, so when the shaft rotates it forces the two plates apart, this is what moves the brake piston
better photo of the inside's
now, you can see the shaft is all cruddy, this is the part that passes through the caliper body, the build up of rust causes the shaft to stick slightly, so the pads are being held in contact with the discs, a little.
two reasons for this, the shaft does not seem to have much passivation on it, so it will go rusty, and the movement of the shaft is in and out as well as rotation, i.e. when you put the hand brake on, the shaft moves in, this tends to pump water past the seals on the outside of the caliper, so guaranteeing corrosion
could it be repaired? yes, you can get overhaul kits for 25, but with the price of new calipers at around 45 , its not really worth it
I'm a little ocd on finding out how thing work and why they failed
anyways, the new caliper was a non exchange unit, so thought i's try and pull the old one apart.
not too difficult really.
the lever that the cable hooks into is connected to the shaft at the left end, where my finger is.
shaft rotates, and the plate stays still, there are 3 ball bearings between the two parts, sitting in ramps, so when the shaft rotates it forces the two plates apart, this is what moves the brake piston
better photo of the inside's
now, you can see the shaft is all cruddy, this is the part that passes through the caliper body, the build up of rust causes the shaft to stick slightly, so the pads are being held in contact with the discs, a little.
two reasons for this, the shaft does not seem to have much passivation on it, so it will go rusty, and the movement of the shaft is in and out as well as rotation, i.e. when you put the hand brake on, the shaft moves in, this tends to pump water past the seals on the outside of the caliper, so guaranteeing corrosion
could it be repaired? yes, you can get overhaul kits for 25, but with the price of new calipers at around 45 , its not really worth it