For a while, I've had a noise emanating from my rear brake, caused by one, or both of the pads touching the rotor at certain points. Being the cheapest hydraulic system from Tektro, the HD-M300, I kinda lived with it, as I just put it down to manufacturer cheapness.
I dialled out most of the noise with adjustment of the caliper, but could never totally eradicate it. So today, I made the decision to sort the bloody thing out, or replace the caliper and rotor.
Comparing the rear hydraulic action with the front brake, I noticed that the front front brake squeezed the pads both at the same time, but the rear one was only moving the pad on one side.
Took the rear caliper off and it appeared that one of the pistons was sticking in the extended position. I took the pads out, and saw that one of the pistons wasn't returning when the brake lever was released.
From previous experience of freeing sticky pistons on car calipers, I inserted the handle end of a wrench between the pistons and squeezed the brake lever to extend the pistons. The wrench stopped the pistons popping out, but was thin enough to allow them to extend a bit further than they normally would.
Then, I removed the wrench, sprayed the piston area with contact cleaner and pushed the sticky piston back in. Did this a few times, and hey presto, the piston is now returning as it should. No more noisy brakes
The Tektros have needed next to no maintenance over 4000 miles, apart from pad replacement and a clean.
Considering they are at the arse end of the cheap scale, I have been very impressed with their performance and are far better than the rim brakes I had on a previous bike.
I dialled out most of the noise with adjustment of the caliper, but could never totally eradicate it. So today, I made the decision to sort the bloody thing out, or replace the caliper and rotor.
Comparing the rear hydraulic action with the front brake, I noticed that the front front brake squeezed the pads both at the same time, but the rear one was only moving the pad on one side.
Took the rear caliper off and it appeared that one of the pistons was sticking in the extended position. I took the pads out, and saw that one of the pistons wasn't returning when the brake lever was released.
From previous experience of freeing sticky pistons on car calipers, I inserted the handle end of a wrench between the pistons and squeezed the brake lever to extend the pistons. The wrench stopped the pistons popping out, but was thin enough to allow them to extend a bit further than they normally would.
Then, I removed the wrench, sprayed the piston area with contact cleaner and pushed the sticky piston back in. Did this a few times, and hey presto, the piston is now returning as it should. No more noisy brakes
The Tektros have needed next to no maintenance over 4000 miles, apart from pad replacement and a clean.
Considering they are at the arse end of the cheap scale, I have been very impressed with their performance and are far better than the rim brakes I had on a previous bike.