How-To Guide
How to Repair a Tire
A proper puncture repair is a plug and a patch, put in from the inside with the tire off the wheel. Check that the tire can be repaired, then step through a real one: a nail hole in a passenger radial, fixed with an Xtra Seal 11-415 patch.
Can This Tire Be Repaired?
Answer three questions before you start. These are the industry limits for passenger and light truck tires.
Where is the damage?
How big is the hole?
What kind of tire?
Repairable: plug and patch it
The hole is in the tread and 1/4 in or smaller. Fill it with a plug, then patch it from the inside. The steps below walk through it.
Not repairable: replace the tire
Repairs are only allowed in the tread area. Damage in the shoulder or sidewall can't be fixed safely, so the tire needs to be replaced.
Too big to repair: replace the tire
Passenger and light truck tires can only be repaired when the injury is 1/4 in or smaller.
Check the chart for your repair unit
Truck, farm and OTR tires follow their own repair limits. Check the chart that comes with the repair unit, or call us at 800-328-7400 and we'll help you pick one.
Step Through a Real Repair
Here's a nail hole in the tread of a passenger radial getting a proper plug and patch repair, one step at a time.
Step 1 of 8Remove & Inspect
Tire cross section
Step 1 of 8
Remove and Inspect
A proper repair starts with the tire off the wheel. That's the only way to see the inside, where damage from running low hides.
How to Inspect
- Mark the injury, let the air out and take the tire off the wheel.
- Pull the nail or screw and note the angle it went in. It has to be in the tread area, not the shoulder or sidewall.
- Probe the hole to check its size. 1/4 in is the limit for passenger and light truck tires.
- Look over the inside of the tire for cuts, rubber dust or creases that mean it was driven low or flat. If you find any, replace the tire.
Why It Matters
A plug pushed in from the outside never shows you the inside of the tire. Damage from running low or flat can hide there and fail later.
Get It Right: Never repair a tire worn to 2/32 in of tread, or one with a bulge or a separation.
Step 2 of 8
Clean and Scrape the Liner
Clean the inner liner around the hole before any buffing. Mold release and dirt keep the patch from bonding.
How to Clean It
- Spray pre-buff cleaner on the liner over an area bigger than the patch.
- While it's still wet, scrape the area with a liner scraper to lift the dirt and release agent out.
- Wipe it off and let the area dry.
You'll useXtra Seal 14-100 Pre-Buff CleanerREMA TIP TOP 28 Liner Scraper
Why It Matters
Scraping while it's wet pulls the contaminants out instead of buffing them into the rubber.
Get It Right: Don't buff first. Buffing a dirty liner just grinds the mold release into it.
Step 3 of 8
Ream the Injury
Clean out the injury channel so the plug can fill it and bond. Work from the inside of the tire, along the angle of the hole.
How to Ream It
- Chuck a carbide cutter in a low speed drill.
- Run it through the hole from the inside, following the path the nail took.
- Run it in and out a few times to clear loose steel and rubber from the channel.
You'll useRepair tools and cutters
Why It Matters
A clean channel lets the plug bond to rubber all the way through the tread, which keeps water away from the steel belts.
Get It Right: Match the cutter to the size of the plug or stem you'll use.
Step 4 of 8
Fill the Hole With a Plug
The plug, also called a stem, fills the injury so water and dirt can't get into the casing.
How to Plug It
- Coat the plug with vulcanizing cement.
- Push the lead wire through the hole from the inside, then pull it from the outside until the plug fills the channel.
- Leave a little of the plug sticking out on both sides. You'll trim it later.
You'll useXtra Seal 13-621 PlugsXtra Seal 14-008 Cement
Why It Matters
A patch alone only seals the inside. Without a plug, the hole stays open to the steel belts.
Get It Right: Follow the plug maker's instructions for cement and set time.
Step 5 of 8
Buff the Liner
Buffing gives the patch a fresh, textured surface to bond to.
How to Buff It
- Trim the plug's inside end close to the liner.
- Center the patch over the hole and outline an area a little bigger than it with a tire crayon.
- Buff inside the outline with a low speed buffer until the surface is even and textured. Don't buff through the liner.
- Vacuum or brush away the dust. Don't blow it off with shop air, which can carry oil.
You'll useXtra Seal 14-359 Buffing Wheel
Why It Matters
The patch only bonds where the liner is buffed. An unbuffed spot at the edge is where a patch starts to lift.
Get It Right: Keep the buffer at low speed. Too fast burns the rubber.
Step 6 of 8
Cement the Buffed Area
Vulcanizing cement starts the bond between the patch and the liner.
How to Cement It
- Brush a thin, even coat of vulcanizing cement over the buffed area.
- Let it dry completely. It should look dull, not wet.
- Keep fingers and dust off the cemented area.
You'll useXtra Seal 14-008 Cement
Why It Matters
Patching over wet cement traps solvent under the patch, and it won't bond.
Get It Right: Go by the dry time on the can. A cold shop takes longer.
Step 7 of 8
Patch and Stitch
Set the patch over the hole, lined up the right way, and stitch it down.
How to Patch It
- Peel the protective cover off the patch without touching the bonding side.
- Center it over the hole with the arrow running bead to bead.
- Stitch it down with a stitcher, working from the center out to push out trapped air.
You'll useXtra Seal 11-415 PatchEverhard 6004 Stitcher
Why It Matters
Radial patches are built to flex with the tire's cords. Turned the wrong way, they can't.
Get It Right: Stitch the edges well. That's where trapped air hides.
Step 8 of 8
Seal and Remount
Finish both sides of the repair, then put the tire back in service.
How to Finish
- Trim the plug flush with the tread on the outside.
- Brush inner liner sealer over the edge of the patch and the buffed area around it.
- Remount the tire, inflate it to the pressure on the vehicle placard and check the repair with soapy water.
- Balance the tire and wheel before it goes back on.
You'll useXtra Seal 14-128A Liner Sealer
Why It Matters
Liner sealer seals the buffed area and the patch edge so air can't work its way under the patch.
Get It Right: Repairs can't overlap. If the tire needs another one later, it has to be clear of this patch.
All 8 Steps Done
Plugged, Patched and Sealed
Here's the whole repair at a glance.
The plug fills it, the patch seals it
From the inside, with the tire off the wheel
- Can It Be Fixed
- Tread area, 1/4 in max
- Clean
- Pre-buff cleaner, scrape wet
- Ream
- From the inside
- Fill
- Cemented plug
- Buff
- Low speed, past the edge
- Cement
- Thin coat, dry
- Patch
- Bead to bead, stitch out
- Finish
- Trim, seal, remount, balance
Example based on an Xtra Seal 11-415 patch and 13-621 plugs on a passenger radial. Always follow the instructions packed with your repair units.
Pick the Right Repair
Repair Units for Every Job
The steps are the same for every plug and patch repair. What changes is the repair unit and the size of tire it's made for.
Passenger and Light Truck
Radial Patches
Oval radial patches like the 11-415 cover nail holes up to 1/4 in in the tread, with a plug in the hole.
Shop PatchesOne Piece
Plug Patch Combos
A stem and a patch in one unit, pulled through from the inside. Same prep, one less part.
Shop CombosOn the Bench
Repair Chemicals
Pre-buff cleaner, vulcanizing cement and inner liner sealer for every repair.
Shop ChemicalsStock the Repair Bench
Everything for plug and patch repairs, from cutters and buffers to patches, cement and liner sealer.