The leak is usually easy to spot. Sealant collects on the outside, and may build up into a grass-and-sand-covered chunk. But once the tire is cleaned and off the rim, you may not be able to find your leaky spot again.So... before dismounting the tire.

Before bleeding the air from the tire, let it sit a minute with the valve-side of the wheel down, valve aiming straight up. This drains any sealant that may have collected in the valve stem.Now rotate the wheel so the valve is at the top, aiming down. (This keeps the sealant from squishing out through the valve as the tire mashes flat on the ground.) Bleed the air from the tire.

Now break the tire away from the rim by pulling it sharply to one side. Work around the rim, breaking the seal on both sides.

Next squeeze the bead of the tire in to the center of the rim, all the way around the wheel. This puts both sides of the tire's bead in the lowest spot of the rim, so it can stretch over the rim more easily.

Lever the tire off the rim, on one side only, right where the puncture is located. Don't "dig in" so deep that you catch the tire liner (if you're using a tubeless conversion system such as no-tubes). Plastic tire levers are less likely to damage the rubber coating on the tire's bead. (If your tire lever cuts into the rubber on the bead, it may not re-seal properly.) Pull about 1/4 of the tire's circumference off the rim.

Now rotate the wheel, so the open area is at the bottom. The sealant will puddle in the tire at this spot.Pour the sealant out into a container.

On the inside of the tire, clean the spot of the puncture with a paper towel. Get it as dry as you can. If the rubber seems to be "rubbing away" to expose the cords, stop wiping! Blot the sealant by touching gently, then proceed to drying.

Finish drying the puncture-area with a blow-dryer, or -- on the trail -- by exposing to sunlight. If you won't be riding for a couple of days, let the tire dry as long as possible before patching. If you put the patch on while the tire is still wet, it may come loose.

Wait until the glue is dry. (It will still be a bit "tacky," but won't pull away from the tire or spread when touched.)Press the patch or tire boot firmly over the puncture. Consider inflating the tire with a tube in it and riding non-tubeless for a couple of days while the bond matures.

Wipe the exposed tire bead (the part that will contact the rim) clean of dirt and sand.Dump your sealant back into the tire.Dip into the sealant with your finger, and apply a coating of sealant to the exposed bead of the tire.

Rotate the tire so the separated area (and the puncture) are at the top. With both hands working towards the center, press the tire bead back over the rim.

Next work around the tire, forcing the bead out against the side of the rim. Using both hands, push your thumbs down in the center of the tire, while your fingers drag the sidewall of the tire outward. When it looks like the bead is sitting against the sidewall all the way around, you're ready to inflate.

Use a CO2 power inflator for on-trail repairs. A mini-pump doesn't provide enough air pressure to seal the tire during initial inflation.

If the tire won't inflate because the valve is plugged with sealant, see our "valve cleanout" page.

Before putting the tire back on the bike, work the sealant around the tire's bead. Holding the wheel horizontally, tip it slightly down, then slightly up. Rotate the wheel about six inches, and repeat. Continue until you've worked all the way around the wheel a couple of times.

Turn the wheel over, and repeat the tip-down, tip-up process all the way around the wheel. This gets sealant on the opposite bead of the tire.

You're now ready to put the wheel back on the bike and ride.

Having problems with your tubeless system?  See our Tubeless Hints page.