Hi there… John Talley here with Partzilla.com.
Today we’re gonna take a look at the fork seals on your motorcycle.
Specifically, we’re gonna give you the basics on how your fork seals work…
how you know it’s time to replace them… and some general steps that will help
you get through the process of replacing your fork seals when the time comes.
Now, every manufacturer—and every model—is going to be a little different.
In fact… we’ve already done a fork seal replacement on a couple of units, and you
can check out the description below to find links to those videos…
But a basic understanding of the job can help you when you order parts and head for the toolbox.
But before we start working on them, let’s get a better understanding
of how your fork seals work on your machine. So if you’re ready, let’s go.
[intro music]
So how does the front fork work on a motorcycle? Well, you’ve basically got two parts:
First, we have a spring that holds the weight of the motorcycle up. When we hit
bumps on the road or trail, it compresses and allows the wheel to handle those undulations.
Second, we have a dampening system. That’s inside the tube, and that
helps smooth out the movement of the spring to give you a consistent ride.
Now it’s this dampening system where the fork seals enter the picture.
See, the dampening works by using oil that is pushed in
and out of small holes inside the fork tube… and the resistance of the oil moving
through those holes is what dampens—or slows down—the reaction of the spring.
And the fork seals help keep the oil in the tube.
Now, how are you gonna know it’s time to replace those seals?
The surest indicator is pretty straightforward: you’ll see it. If you see oil here on the fork
leg or suddenly you find a bunch of dirt sticking there? You might have a leak.
In some cases, you might even end up with fork oil on the inside of the front fender or even worse…
you might end up with it on your brake rotor. And oil and brake rotors don’t play well together.
From a handling standpoint, you might also feel the front end getting spongy or soft.
But the seals go, it doesn’t get better, and the oil leaks out,
and it can mess up how your machine rides and if it gets the brakes… how it stops.
So here you are: you see the oil, you feel the sponginess through the handlebar…
so it’s time to replace the seals.
Unless it’s the rare circumstance where a seal is defective or was damaged somehow, go ahead and
do both sides… because when these things wear, they tend to wear at a pretty consistent rate.
So if you’re seeing leaks on one side? They’re coming to the other side in short order.
Now, when you’re ready to do the job, a clean workspace is essential. We’re talking about moving
parts here with very tight tolerances, so dirt and contaminants can do a number on these parts.
Another thing… arrange your parts in the order they come off the motorcycle AND the fork tubes.
There’s a lot of parts that look similar, and it’s easy to get ‘em mixed up if you’re not careful.
So take your time, stay organized, and keep your parts in order.
You also need to pay attention to the orientation.
When you’re taking the old seals off, pay attention to how they go on and which side is up.
Might even want to mark one side with a marker or something to remember how they go in place.
Now, you want to make sure your motorcycle is on a secure lift to hold it in place.
You’re basically going to take the front end off, so something’s gotta hold it up.
You also need to make sure the motorcycle is secure on the stand and anchored down
on all four corners… because you sure don’t want one falling on you.
Next, you’ll need to get the brake caliper removed. Now generally, that’s going to be
just a couple of bolts holding the caliper in place. Some bigger machines might have a
caliper on both sides of the wheel, so obviously you’ll need to get both if that’s the case.
Then, you’ll want to loosen up your axle and drop the wheel out.
The next part of the process will differ from unit to unit. You’re going to need to dig down to the
top of the triple tree… the clamp that holds the fork tubes in place. You’re gonna need to deal
with the plastics or the instruments to get there, but it’s the only way to get the fork tubes out…
But before you remove the tubes,
loosen the caps at the top of the tubes… they’re on there pretty tight, and it’s a lot easier
to break them loose when the clamps are still keeping the tubes in place.
Then, you can just loosen the pinch bolts and drop the legs out.
Now, once you’ve got the fork legs out, you’re going to finish
removing those fork caps so you can get the old oil out.
Then wipe everything down. Might even want to use some
brake cleaner to clean the fork tubes before you start pulling things apart.
Now, wrap some electrical tape around the fork
tubes. Doesn’t need to be a lot… just enough to protect the tube from scratches
as you guide your old seals up and off the tube and the new ones back on again.
All right, time to get the old seals. It’s going to be some combination
of rubber dust seals and maybe a couple of metal rings depending on your particular model.
With the fluid drained and the old seals out, now’s a good time to inspect the fork tubes.
If there’s a little pitting, you can get some of that out with some polish.. but nothing abrasive.
These tubes need to be as smooth as possible so they seal properly.
Then replace your seals in the order… and orientation… they came off.
Now it will be important.. particularly if your machine has a little time on it… to wrap
some electrical tape especially on the upper part of the fork tubes. Because believe it or
not… as that chrome starts to break up and get a little bit older… when we go to put the new
seals on it’ll just slice straight through it. So we want to protect the new seals from any
damage or irregular surface that may be on the upper part of your actual fork tubes themselves
Once you’ve got the seals on, you’ll need to refill the tubes with oil. Your service manual
will tell you exactly how much oil your forks take. I use the depth gauge on a digital caliper…
set it just a tick deeper than the manufacturer’s oil level, and then fill to that point.
Then I remove the caliper and add a little more oil to top it off.
Then, get your fork caps back on. Just get them closed up… you can torque ‘em
once you get the fork legs back on the motorcycle.
Then, reverse the process to get the fork legs back in place.
Get them in the triple tree, torque everything down.
Replace your instruments… then install your wheel and your calipers.
Once that’s done, you’ll need to make sure your forks are parallel so that the
motorcycle will track properly. The process varies from model to model,
but in our Goldwing and Gixxer fork seal videos, we show you the basics of that process.
Well guys, that just about wraps it up. Just remember: keep everything clean,
keep your parts in order, and make sure your motorcycle is super secure on that lift.
Listen, if you have any questions or comments, why don't you leave in the section below
and I'll do my best to answer them.
Hey, if you like what you see, why don't you go and hit that subscribe
button. That way you can keep up with whatever I'm working on next.
We just want to say thank you for shopping here with us at Partzilla,
and we will see you in the next video.
Y'all have a great day.