If you’re riding tubeless tires, then you know the importance of keeping them properly sealed. Topping up your sealant is an easy way to ensure that your tires stay airtight and perform at their best.
When it comes to topping off your tire sealants, there are few factors that will determine when and how often this should be done: terrain type, temperature, your tires quality, how often you ride... Some folks say to check the sealant level every couple of weeks, some other say the sealant lasts as long as the tyre itself. I think it's a good practice to check and top up at the start of the year before I'm off for some serious adventure, and later in mid-season, as part of a general check up.
Now let's get into actually doing it - here is a simple step by step guide on how to top up tire sealants, without taking the tires off the wheel.
Here's what you'll need:
sealant (I chose Stans NoTubes The Solution Tyre Sealant, available in Halfords, Tredz and many more stores)
sealant injector (plenty of options available online). It's really just a syringe with a rubber tubr that can fit in the valve. Mine came with a handy tool to unscrew the valve cores
a tool to unscrew the valve cores (pliers, or a specific tool)


Step by step how to top up tubeless tires keeping them on the wheel:
1) Depressure the tires and unscrew valve core from each tyre – some valves have small slits which can also work for unscrewing purposes too so use whatever works best for yours specifically.
2) Shake the sealant bottle - first rotate it upside down, then shake it really well. You want all those important particles to mix in the solution.
3) Check how much sealant you've got left in the tyres. Tip: use a cotton ear bud (important: remove the cotton bit!) and put it inside the valve just as you'd check the car oil level with a dipstick. It won't tell you how much exactly is there, but if it comes out dry then at least you're sure you really need to top it up.
4) Fill the injector with the solution. How much depends on how big is your tire, how much sealant you've got left in tire... I've added around 40ml in the injector after seeing around 7mm reading on my dipstick :)
5) Insert an injector tube into one valve opening while making sure not too much pressure builds up inside; now slowly push out all contents
6) Replace the valve core and pump up the tire
7) Rotate the wheel and move it sideways in all direction so that the sealant has a chance to get in contact with all sides of the tyre
8) Repeat steps above again with other wheel
And voila! You've successfully topped up those seals without breaking sweat.




