A recent post I responded to recently, prompted this entry. That post was a simple brake sticking enquiry.
For the love of whichever deity you choose, do not, and I repeat, do not, disassemble a break calliper. The spring tension that gets released when you dismantle it, will send various washers and springs flying all over your garage. If you manage to find all the parts again, you’ll have issues with keyed washers, roller bearings and springs when reassembling.
So, my process of fixing a sticky calliper is quite easy. I’ll assume you’ve already tried the calliper without the cable attached. Most of the time, it will be down to old worn cables and cable housing. Note that I’m doing a dual pivot calliper here, no single pivot, cantilever or disc brakes. I might however cover those in another post sometime in the future.
What you’ll need
- 5mm Allen key (for the majority of nutless brakes)
- GT85 or similar cleaning spray
- Good quality thick chain oil
- Toothbrush or stiff brush
So, first off, remove the calliper from the bike to work on it. Remove the brake blocks and store them away from where you working, as you don’t want to contaminate them.
Now squeeze together the arms, and look down the middle from the side, most brake designs will have a roller between the arms, and a pivot on both arms. Your objective is to get all the gunk and general nasties out of the pivots and rollers.
Add the red straw to your spray can, and go to town spraying it into the roller, work the arms. Do the same with the pivots. Wipe it down wit the rags, and scrub it with the toothbrush.
Repeat until the calliper operates a fair bit smoother. When satisfied the brake is working well again, set it aside to dry off.
Now, with clean hands, get hold of the brake blocks, have a look and see if you can see any embedded metal fragments in the block. Use a pick to pick out anything in there. If they are an older block, you may get notice they look a little shiny and glazed. Simply run a file over the top to remove that surface. Reattach the brake blocks to the calliper, making sure you have the left and right blocks on the correct sides. Drip a small amount of lube into the roller and all pivots wiping off any excess on the calliper.
Clean out the brake bolt recess in the frame, clean the hollow bolt and Reattach the calliper to the bike, realign your pads to the rim, and tighten up. You can apply a drip of loctite to the thread if you need, ive never need it and just greased the thread which has been enough.
Jobs done, go and ride and enjoy your enhanced breaking power.