I like ride by bicycle. I have Merida Matts TFS 300 with Tektro Draco brakes. After first racing season, I decided to clean and bleed the brakes.
I have fully disassembled rear caliper and lever, so this is my report. Sorry for a quality of photos (all clickable) :(
- TORX keys
- Allen key
- Key for 8 and 7
Ok, let’s go. Remove the pads, be careful, the pads must be completely clean of oil (if you will not replace it by new).
Now you can see pistons. The pistons are quite fragile, so try not to use some heavy instruments with it.
In disassembling a caliper, there are two problems: sometimes it is really hard to remove TORX bolt and also hard to remove pistons. In my case, there was no problem with TORX, but I couldn’t take off the pistons.
But there is a chance: after you remove the pads, try to press several times to the lever, and may be one or two pistons simply get out of their positions.
I didn’t do that, I disassembled caliper on two pieces and realized that I have to go to the bike service. Actually you can find many solutions how to remove pistons for example with a pump.
As you can see everything quite dirty.
Just great. Don’t lose this very small rubber ring (on the right side is the photo). Now with tweezers remove O-rings and carefully observe it, if it looks not good - replace by new. WARNING: O-ring has on the one side small track. So don’t forget right position O-ring, the small track must be on the bottom when you put O-ring into caliper.
Huh, after all, wash everything from the old mineral oil, dirt and so on with laundry soap.
When everything will be dry, assemble the caliper. Put O-rings, smear the pistons with oil a little and put into the caliper with little pressure. Do not forget about small ring between caliper pieces, and fully assemble it. Good. Put the caliper aside.
Let’s do it with the lever. I’ll don’t describe everything because it is quite simple to disassemble it. So I explain problems which I had.
Ok, now problems, which I had.
First is arm, (a black detail, you push it by fingers), it can’t be removed.
Next is the first washer, which you have to remove first of all. This very hard. I said before about tweezers, forget it, I took off it only with sharp pliers. And when you will assemble the lever, again to put it inside will be hard.
So, that all.
I thought I will write about bleeding, but I did it first time, and had problems.
Way to bleed brakes from down to up not working with this brakes. Because bleeding pin in a caliper, very poorly sealed. And during the bleeding the oil can flow over the pin. Or you bleed from up to down or try to seal this pin with Teflon tape.
On the Internet, you can find many articles about it.