Replacing the Front Fork Seals on the Telescopic Shocks
The front fork seals on a CT are NOT very heavy duty and often start leaking if they are damaged in any way.
This damage can be caused by; old age, continuing to compress the shocks by over tightening the hold down straps when transporting your CT, or heavy riding where the front shocks travel to their extreme ends and are thus abused.
You can usually tell if you need to replace your front fork seals if one of the following is evident;
You see a fluid leaking from the middle to lower section of your front telescopic shocks.
You feel that your front telescopic shocks are "riding hard" and jaring your hands on the handlebar.
To replace your front fork seals is not a complicated job. It usually takes a few hours of your time and some common tools found in most CT'ers tool box. Here's what you'll need.
Metric tool set, sockets & ratchet and open/box ended wrenches (10mm, 12mm, 14mm, 17mm, 19mm). You will also need to have a pair of pliers that can remove circlips, something to help you seat the new fork seals in place (see photos below), and an adjustable crescent wrench.
Here's a drawing of what the inside of the front fork look like.
Please read the entire proceedure once and then as you work, read each step completely and examine the photos to make sure you understand the proceedure, then try doing what is described.
Remove both of the top cap bolts from the top of the forks.
You need to pull the cap bolts all the way out to let air in and thus the fork fluid out. There is an o-ring on the cap bolts, so it might take a little pulling to remove them completely, do that carefully, don't damage the o-ring on the cap bolt.
Your forks should be held in place by the pinch bolts at the bottom of the triple tree. If they want to slide down, check the pinch bolts for tightness as you are really not ready for the forks to be removed.
Find a container to hold any old fork fluid, at least a pint or 16 oz in size.
One at a time, while holding your container under the drain bolt, unscrew the drain bolt and remove it.
Draining the other side.
If the drain bolt falls into your container, that's OK. Putting it back is one of the last steps in this proceedure. You may want to pump the forks up and down to see if there is any more fork fluid that you can get out. You probably won't get all of the fluid out, however, the more you get out now, the cleaner the entire process will be. Do the other side fork next. Dispose of the old fork fluid properly.
Place the CT on it's center stand, if your CT has one. If not, put the skid plate on a box or crate or something to hold the CT up and level, side to side. If the front wheel is off the ground slightly, that's the best position, if not, put something heavy on the rear cargo rack to get the front tire slightly off the ground. When you remove the weight of the front wheel and tire, the CT will need to be sitting on it's rear tire.
Disconnect the speedometer cable from the front wheel drum. The bolt needs to be completely removed and then the round plastic housing will just pull straight out of the brake drum.
Some CT'ers say you need to disconnect the front brake cable, however, I think you can leave it attached and simply remove the brake assembly from the brake drum when you do the next step. The choice is yours.
Pull the cotter pin from the axle nut and remove the axle nut.
Pull the axle bolt out of the brake drum and forks. If the axle bolt is hard to move, put the nut back on flush with the end of the axle bolt and tap with a piece of wood to loosen the axle bolt then, remove the nut. Continue to pull the axle bolt out and pull the entire wheel and tire assembly down and forward away from the forks. Once the brake assembly clears the forks, you can pull the brake assembly away from the brake drum and just let it hang there while you store the wheel & tire.
This would be a good time to inspect the brake shoes and the interior surface of the brake drum. Your brake shoes should have a fair amount of material left on them and the brake drum should be smooth on the inside.
Take the brake drum assembly, still attached to the brake cable and lift it over the handlebars and let it hang between the seat and the handlebars.
Remove the front fender, it is held on with 4 small bolts.
Romove the headlight from the bucket. The main removal screw is at the bottom of the headlight. You can leave the headlight wires attached if you want, just let it hang or you can remove the wires from the headlight. The small screw on the side of the headlight ring is for adjusting the headlight beam, side to side, leave it alone.
Remove the headlight bucket mounting screws that are held in place inside the headlight bucket. You can lift the headlight bucket and headlight, if still attached by it's wires, and the speedometer cable, over the handlebars so the whole thing can be out of the way.
Remove the fork pinch bolts at the bottom of the triple tree.
If your forks do not slide down and out, you may need to open the pinch bolt area to release the forks. There are two possible methods of opening the pinch bolt area; 1) force a flat blade screwdriver into the gap in the pinch bolt area, or 2) put the pinch bolt back in backwards with a strip of hard metal in the pinch bolt gap and screw the pinch bolt against the strip of hard metal.
Both methods are designed to open the gap just enough to let the forks slide down and out. However, either method needs to be done with care as to not damage the pinch bolt area or crack apart the triple tree in that area. There is a chance that the forks have never been removed and might be tightly stuck in place, perhaps with some rust. Some penatrating oil can be used over a period of time (sometimes hours, sometimes days). If you decide to get out a hammer to help the fork get loose, be careful, use something that will compress slightly, like a piece of wood, for the contact surface. Some CT'ers have purchased a longer bolt to fit in the top of the fork, where the cap bolt was located. Be sure to screw the longer bolt "in all the way' and do not "over pound" on the bolt, as you may damage the cap bolt threads inside the top of the fork. If your forks came out hard, then make sure you clean them up relly well when before you put it all back together. As the forks slide down and out of the triple tree, you will need to catch and remove the headlight bucket "ears" that were between the top and bottom of the triple tree.
With the forks off your CT, you can seperate the bottom of the rubber fork accordian boot and remove it and the parts above it, including the spring, for cleaning. They should just slide up and off the fork shaft. It's always a good idea to keep the parts in the same order they were assembled, or just do one fork at a time so you can look at the still assembled fork for the order that the parts go.
If your fork looks like the one in the photo below, you were right in thinking the seals needed to be replaced.
Here's where you need to have the special circlip pliers, however, first you need to be able to see the circlip, so clean carefully around the top of the circlip. Eventually you'll be able to find the open ends of the circlip and clear out the holes that the circlip pliers grab onto the circlip. Use the circlip pliers to squeeze the circlip ends together and pull the circlip out of the bottom of the fork tube.
To get the fork seals out, some CT'ers have mentioned using a flat blade screwdriver to wedge it out, some CT'ers have mentioned using a thin screw, driving it into the seal and then pulling on the screw, however both of those methods runs the risk of scratching the fork tube and thus you will never get a good tight fit of the seal on the tube. The following photos show an alternative method.
First compress the fork tubes together, then quickly, jerk the fork tubes apart.
Doing this as often as required to have the fork guide, which is just under the seal, force the seal up and out of the bottom fork tube. If all the fork oil in not out, this can be a little messy, but it doesn't pose any hazard of scratching the fork tube.
Here's a photo of the fork guide that forces the seal up and out of the bottom fork tube using the above non-destructive method.
With the front fork removed and disassembled, now is the time to inspects all of the associated parts. You probably won't need any replacement parts, except for the new fork seals, but there could be a fair amount of rust and junk on the parts. Why not clean them up a bit, make them look as good as possible at this time. If you decide to use any solvents, make sure the parts that were cleaned with solvent are completely DRY (you need an air compressor to blow out some of the small passages). After every thing is clean and dry, we're ready to start the reassembly.
Dirty on Left, Cleaner on Right
Cleaner on Left, Dirty on Right
The tool I use.
Assemble all the parts that go below the fork seals on the top fork tube and slide the top fork tube into the bottom fork tube. You kept everything in order, right? If not, review the diagram at the top of this web page.
Slide the new fork seal, flat side up, down the top fork tube and see if you can use your fingers to get it started into the bottom fork tube. If the fork seal is very loose, you may have the wrong size. It should be a snug fit and you'll only be able to get it started just a little bit or maybe as far as shown below. It's very important that the fork seal be started correctly, pretty close to flat, not tilted a lot, one way or the other.
Some CT'ers have mentioned using a piece of PVC pipe or a PVC union to use as a nice round device to press the fork sela into position, hammering carefully around the PVC part. I've never been able to find a PVC piece that had the correct outside and inside diameter to do the job. Honda even makes a special tool for "seating" fork seals into the bottom fork tube.
My method is very "old school", I seat the fork seal with my fingers, making sure it is pretty "flat", and then use a right sized, flat ended punch, I carefully "tap" it into place, starting at any high spot and then by going all the way around the fork seal several times. It does take some practice, and a soft hand on the hammer. If the fork seal starts to tilt one way, I work on the high side until it is flat again. Eventually it will be seated below the location of where the circlip is placed.
Examine your circlips carefully to see if they have a rounded edge or a flat edge on one side surface. If they have a flat edge, that edge should go "up" to help secure the circlip in place and not be dislodged with abnormal movement of the shocks while you are riding. If you can't tell the difference in the edges, you could have a circlip where it doesn't matter (I've had several of those, and they are working fine over many, many miles).
With the fork seal secured in place, take the rest of the parts that go above the fork seal and install them on the top fork tube. Slide the fork tube into the triple tree, making sure to put the parts that go between the bottom and top of the triple tree, the headlight ears, in as you slide the top fork tube up into the triple tree. If your fork tube came out, only with a lot of work, and you didn't actually clean that area up, try some light sandpaper to get any junk off the top of the fork tubes or inside the triple tree mounts.
If you need to open up the area of the pinch bolt, use the flat blade screw driver or put the pinch bolt back in backwards with a strip of hard metal in the pinch bolt gap and screw the pinch bolt against the strip of hard metal, same as you did to remove the fork from the triple tree as shown above. If you still can't get the fork tube all the way up and you have that longer bolt to fit in the top of the fork, where the cap bolt was located, you can use that with a bunch of washers.
Or, here's another technique for stubborn fork tubes if you have a ratcheting hold down strap. Once the strap is in place correctly, with the bottom part of the strap tight and the top part of the strap so it can slide over the handlebar, you just ratchet the fork up into the top of the triple tree, nice and slow.
Put the top cap bolts in at the top of the forks and tighten. If you still need to do the other fork, go back and do all of that one. With both forks attached by their top cap bolts, rotate the bottom fork tubes and insert the axle bolt to make sure both fork tubes are aligned with each other, then place and tighten the pinch bolts.
Replace the headlight bucket, and the headlight.
Replace the front fender.
Remove the axle bolt from the front fork tubes, place the brake drum in the wheel assembly and mount the wheel onto the front forks with the axle bolt.
Tighten the castle nut on the axle bolt, so that the wheel turns easily, there is no side to side movement of the wheel and so that the cotter pin can be installed.
Connect the speedometer cable to the front wheel drum. Remember the bolt needs to be completely removed and then the round plastic housing will push straight into the brake drum. You may have to rotate the wheel slowly to get the speedometer cable "tang" to engage into the wheel drum. If it's all the way in, you should be able to spin the front wheel and see the speedometer needle move. Once that's OK, then you can screw in the speedometer bolt to secure everything in place.
Make sure the fork oil drain bolts are in place and secure.
If there are any parts left over, figure out where they need to go. Let's hope all you see are the old fork seals. I almost always forget to secure the speedometer cable to the headlight ear, mounting bolt on the left side of the headlight bucket.
Remove the top cap bolts from the top of the forks, so you can get some fork oil down there. The pinch bolts will hold the forks in place while we do this.
Find something to help you get the new fork oil into the top of the forks. I use a very small funnel, some CT"ers have suggested a small syringe. I like the funnel, it's slow, but it's easy to monitor and just flows with gravity, no pressure (thus no splash backs).
The normal fork oil is ATF (Automatic Transmission Fluid). It usually has a 6-8 weight rating and will work fine and is even recommended by Honda. Other types of oils with higher weights can be used, there are even special motorcycle fork oils available at motorcycle shops.
Clean your measuring cup and measure out 140cc./140ml. or 4.7oz. of the fork oil. If your fork parts were never cleaned and dryed, then you want to measure out 125cc./125ml. or 4.1oz. of the fork oil, as there will be about 15cc./15ml. of old fork oil, still in the forks.
Start filling the fork, watching the amount of fork oil in the funnel. You don't want to let it run over the edge and have to drain what's in there and start all over. Guessing on the amount of fork oil in the fork, is not good enough.
When both forks have new fork oil, replace the top cap bolts on the top of the fork tubes, and check your bolts and nuts for tightness. Get your CT on the ground. Some CT'ers say to compress the forks manually by pressing down on the handlebars, however, going for a slow test ride to see how they work, after checking all your bolts, is also OK.
Watch for leaking and don't abuse your fork seals, they should last a long time.