This instructable will detail how to rebuild a set of Crank Brothers Acid pedals. Note that this instructable is for the version of the pedals with loose cup and cone bearings. I bought a used pair of these pedals on eBay along with a couple pairs of cleats. When I received the pedals, they were in serious need of a rebuild before use. After doing some searching on the internet, I found that Crank Brothers sells rebuild kits and instructions on how to rebuild those versions of the pedals that come with cartridge bearings but I couldn't find anything on the loose bearing kind. This project is a fairly simple task to undertake.
Please note however that I am in no way responsible for what you do with or what happens due to this instructable or anything left out of it. Undertake it completely at your own risk and only if you are comfortable with a project of this type. If you fail to get the pedals back together correctly, they could fail while riding potentially causing a serious injury, crash, or both. If anything looks worn out or you are in anyway uncomfortable taking this risk into your owns hands, seek a professional.
Step 1: Tools/Parts You Will Need
Torque wrench with appropriately sized socket for the nut inside of the end cap. In my case that was a 9mm socket.
Tweezers. These really help reach into tight places and handle the loose balls from the bearings.
Hex wrench that fits in the spindle. You will need this to remove the pedals from the bike and to take the spindle out of the pedal body.
Grease. I chose to use Phil Wood waterproof grease. It is kind of expensive, but the best grease I have found.
Small screwdriver to pry out the end caps if like mine, yours aren't threaded.
Loctite. This isn't necessarily a requirement, but I chose to use it for added security from the pedals loosening over time.
Rag. Good to work on so your work surface stays free of grease.
Degreaser. You need something to get the old grease out/off of the existing parts.
Step 2: Disassemble the Pedals
1. If you haven't already done so, remove the pedals from the bike.
2. Next, pry out or unscrew the end cap depending on the style you have. Mine were plastic and just pushed in. You can see in the first picture how it got kind of beat up as I was prying it out. Basically, you just need to get something down into the pedal next to it and pry it out without damaging it to the point where you can't use it again.
3. Once you have the end cap out, set it aside. You should now see a pair of hex nuts on the end the end cap was previously covering as shown in picture #2. Loosen the outer nut using the socket on the nut and hex wrench in the spindle on the other end. Set the nut aside.
4. Remove the keyed flat washer. This is best done by reaching in and grabbing it with the tweezers. It should lift straight out. Note that you cannot turn it since it is keyed. Set the washer aside.
5. Grab the second nut with the tweezers and unscrew it. Be careful here as the spindle can be removed after the second nut is off and the loose balls in the bearings can fall out. Once you have the nut unscrewed completely, set it aside.
6. Carefully pull the pedal spindle out the other end of the pedal body and set it aside. Be careful that you don't drop any of the ball bearings and that none are still stuck to the grease on it.
7. Remove the remaining ball bearings with the tweezers and place them in something so they can't roll away. A plastic cup works perfectly. My pedals had 29 bearings in each pedal, so a total of 58. Keep track of how many you remove from each side so you can put them back together the same way.
8. Slide the rubber seals off the small end of the pedal spindles and place the aside. If they are torn or worn at all, I would suggest looking for replacements. I don't know if the seals in a rebuild kit for cartridge bearing type pedals will fit these or not. This seal is the only thing keeping dirt and water out of the inboard bearing so it is critical to keep the pedals operating smoothly.
Step 3: Degrease Everything
This step is pretty simple. Using your favorite degreaser, clean everything up so it looks nice and new. Pay special attention to the cups, cones, and ball bearings. You should now have all of the parts as shown in the picture. Make sure you don't lose anything or you won't be able to put the pedals back together safely.
Step 4: Reassemble the Pedal
Now put your pedal back together in the opposite way you took it apart. The order for me was to replace the ball bearings on the inboard side and add grease. Then insert the pedal spindle into the pedal body. You will then need to press it in the whole way as you flip the pedal such that the outboard pedal bearing is on the top. While still pressing the spindle to hold the inboard bearings, replace the ball bearings with grease on the other side.
The next step is to start replacing the nuts. Start with the one that is the cone for the bearing. This one does not get tightened as tight as possible. With loose bearings, you want it just tight enough that there is no play between the pedal body and spindle but not so tight that the pedal doesn't turn smoothly. Now place the keyed washer back onto the spindle. Finally, put the outer nut back onto the pedal spindle. You can tighten this one more. Be sure to look up the recommended torque for your size nut. I actually put some removable loctite on mine to ensure that the nut doesn't come off. The last step is to replace the end caps and seals to keep dirt out of the bearings.