Tubeless question - losing sealant when topping up pressures

[jimmy156]

losing a small spurt of sealant as the pump engages / disengages; I am assuming this is normal and unavoidable and part of the reason why sealant needs topping up periodically?

It feels like a stupid question to ask, but I am using a foot pump with a presta valve adapter, rather than a dedicated bike pump (its just what i've got and has worked for years so never bothered to buy anything else), so I am wondering weather I am losing sealant when I shouldn't be.

On a related note... when I come to top up the sealant and I need to remove the valve core, how do I avoid a messy sealant volcano when deflating the tyre and how come the sealant doesn't try and seal up the valve and turn it into a clogged up mess.

Thanks in advance and sorry if these are stupid tubeless newbie questions. I did google it, but couldn't find an answer!

[bobbo89]

Valve needs to be somewhere in the top half of the wheel between 9 and 3 o'clock so that as much sealant as possible is sat at the bottom away from it when you open it.

I tend to find there's always a tiny spurt of sealant when opening the valve but only a tiny amount and only what will have been sat in and around it.

[jimmy156]

That might be the most obvious thing that I have never thought of I will make sure to do that now! As you say, its only ever a tiny spurt of sealant that I have lost.

[bobbo89]

I think if you're using a foot pump the natural thing to do is to get the valve at or near the bottom of the wheel as it's closer to the pump.

As for topping up sealant, I tend to remove the core with the valve at the top of the wheel then rotate it back to a 8 or 4 o'clock position to top up the sealant so that it can run to the bottom easier.

[dodgyviper]

Sealant can clog up the valve. I carry a v small Allen key for the simple job of pushing the gunk plug back into the tyre.

Spent too long trying to pump it up and wondering why the tyre was just laughing at me.