How To - Change The Oil & Fork Seals On A Cartridge Type Fork (part 2) Video
How To - Change The Oil & Fork Seals On A Cartridge Type Fork (part 2)
This is part 2 of our Fork Seal and Oil Replacement video. Please refer to part 1 for disassembly.
Now is a great time to refer to your owner's manual for parts inspection. This is your order that it's going to go back on, you have your dust seal, retaining clip, oil seal, washer, and your outer and inner bushing. Go ahead and stand it up and put it in a vice. We're using soft jaws on this, so be really careful not to mar your fork leg.
Next, we're going to put the Motion Pro seal bullet on and this is going to protect our dust seal and oil seal from the grooves that hold the inner fork bushing on. Go ahead and grease it up. First we're going to take our dust seal and grease it so that it slides down, next is our retaining clip, and then our oil seal.
A little extra grease in there will never hurt anything. This of course, is our seal grease. Slide that over and then when you get to the bottom be careful and make sure you get over that last groove without tearing any of the seal.
Now we're going to go ahead and remove the seal bullet. Then we're going to slide the washer on, the outer bushing, the inner bushing. This is the one that sits in the groove so spread it a little bit and slide it down until it clips into place.
Now we are going to take the outer fork tube and slide it down. We are going to grab our tusk seal driver and go ahead and drive the bushing and the washer. Just a couple of light taps and you can actually hear the sound it makes when it bottoms out. We're going to go ahead and remove those. And then we're going to drive the seal, the actual oil seal. Once again, go ahead and drive that in, you will be able to hear the different sound that it makes, when it's seated.
Next we want to install the retaining clip. Go ahead and slide that into place and just to make sure it clicks in you can use the seal driver again. You can actually hear it snap. Sometimes a visual inspection to make sure it's seated all the way. Slide your dusk seal on, just using your fingers to put that on.
Now it's time to reassemble. We're going to go ahead and put the push rod into the damping rod and we're going to fill it with oil. You're going to want to fill it nearly to the top. And then, what we're going to do now is were going to go ahead and lift the outer tube about 6 to 8 inches, maybe a couple of times.
Now what we want to do is grab the inner damping rod and run that through its stroke. Do this slowly, because on some of the older ones, the oil will actually squirt right out of the end of the rod, so be careful. What we're doing here is filling the cartridge full of oil and getting the air out of it. It might be necessary to add some more oil, just so that you can feel it as you pull that rod through its stroke, if there is any air left. You want a nice smooth action.
Now it's time to add oil using our tusk, fork oil level tool. When we measure the oil we want to make sure and have everything within the fork except the spring, the damping rod completely compressed, the fork outer tube fully compressed, and we're going to measure from the outer fork tube, down to the oil. Go ahead and refer to your service manual and get your fork oil level height. Set the laser etched marks on the fork oil level tool and basically what you are going to do here is pour oil out of the fork, so it's going to need to be a little bit over filled to get the level correct. Once it starts to suck air then you will know that you are at the correct height.
The next thing we are going to do is pull the damping rod up till it's fully extended. And then, put the spring on, and you have to lift it up as you're putting the spring on, and hold it with your other hand. Then you have your spring centering washer; it goes on next, and then your fork cap. At this point you want to make sure your lock nut is threaded all the way down to give the fork cap as much thread as possible. Then you want to slide the wrench in, it holds the fork screen down and you're going to back that lock nut up against your fork cap. You want to make sure that's fairly tight.
For our next step, we're going to go ahead and pull up our outer fork tube and thread the fork cap back into it. The next thing that you want to do here is set our rebound back to where it was. We are ready to mount it on the bike, and let's go ride.