Fork Seals & Gaskets
About Fork Seals & Gaskets
Fork seals keep oil in and dirt out, so when oil shows on the fork tube or streaks the brake side, the seals are the first suspect. Riders shop here to stop a leak, to replace seals while a fork is open for service, or to fit new dust seals and retainers.
The key to the right seal is its three measurements, written as inside diameter by outside diameter by thickness, such as 41 x 54 mm or 49 x 60.5 x 10.5 mm in the listings. The inside diameter matches the fork tube and the outside diameter fits the slider. Oil seals hold the fluid and dust seals or wipers clean the tube, and many listings are seal and wiper kits that include both.
Retainer clips hold the seal in place. Read the sizes from the old seal, the manual or the listing for your model, and replace seals on both legs. Fit them with a proper driver so they go in square, and take care not to nick the lip on the tube edge.
Brands listed here include JIMS, FACTORY CONNECTION, Drag Specialties, Parts Unlimited and SKF. Pick your bike in the Ride Finder at the top of the page. If the bushings are worn too, see Fork Rebuild Kits; if the tube surface is damaged, see Fork Legs & Tubes. Both are in Fork Suspension & Parts.
FAQs on motorcycle fork seals
How do I find the fork seal size I need?
Read the numbers stamped on the old seal, which usually give inside diameter, outside diameter and thickness in millimeters. You can also use your model's specification or the listing for your bike. All three measurements need to match.
What does a fork dust seal do?
A dust seal, also called a wiper, sits above the oil seal and wipes dirt and moisture off the tube as it slides. This protects the oil seal. Many seal kits include both, so check the listing.
Will cleaning a leaking fork seal fix it?
Sometimes, if a bit of grit is holding the lip open, cleaning under the seal can stop the leak for a while. A worn or torn seal needs replacing, and a pitted tube will ruin the new one, so inspect the tube surface.
Should I replace both fork seals at once?
Yes. Seals wear at similar rates, and the fork is open for oil anyway. Replacing both legs keeps the front end consistent and avoids opening the other leg again soon after.
Is fork oil on the brakes dangerous?
Yes. Oil on the brake pads or rotor reduces braking power. If a fork leak has reached the brake, fix the leak, clean the rotor and replace the contaminated pads before you ride.
