luisgutz

Recently, on my tubeless setup, I've been loosing air after pumping the tyres. I've had this setup for a few years, but this started happening about 2 months ago. Not all the time, but on a regular basis. After pumping both tyres at night, I would find one of the tyres near flat. Some times it's the front, some times it's the back.

I've looked for a leak, but cannot find anything. I've added sealant and try to spread it all over the place. I've had the LBS inspect and replace the inner tape. It all looked good to them.

But it keep happening.

I imagine it could be something with the valves, but other than that i'm lost.

Any ideas what could it be? Any ideas what to try?

dsaul

Take the wheel off and dunk it in a tub of water. There will be air bubbles where the leak is.

choddo

Had this with microscopic holes in the tyre wall (had to bin the tyre, think it was caused by hitting a hole or three at lowish pressure) AND with poor seal on the rim thanks to old sealant dried on it.

Big tub of water indeed a fine diagnostic instrument.

KerryIrons

Beyond the obvious suggestion to dunk in a tub of water, the fact that the problem alternates between wheels does bring the valves into question. Contamination or dried seals in the valves could result in this intermittent issue. But if you added sealant back and forth after each flat episode then all bets are off and it's back to the dunking (or spraying soapy water) as a diagnostic.

mpetry912 

you may not need a whole tub, just use some soapy water, you'll see the bubbles

that's where its leaking

/markp