So i dug out an old bike to discover the tubeless set up on wheel not playing. Its an old wheel so my first assumption was I needed to retape the rim.

Do so. Still leaking air out of the valve fitting.
New sealant. Still doing it.
New value, still doing it.
shim of inner tube under the value to give better seal still doing it.
Assume batched taping and own dumb fault, examine the wheel multiple times search of some other defect, or tear in tape. Nope.

Soooooooo…. anyone had similar, know the blindingly obvious thing I’ve not done/it could be?

Just to be extra irking its the one tyre wheel combo I have that doesn’t pop on to the rim easily… of course it is. Air deff coming out through valve fitting, not bead.

Cheers

9/10 times leaking around the valve is taping in general and once air gets in the channel it just happens to find its way out around the valve.

Stevextc +1

The spoke holes are just slightly better sealed. Probably a gap where the the has dissolved over time and the tapes lifted as there wasn’t any air pressure to push it down.

Could be the valve itself, some valves just don’t work well in certain rims, for example I’ve not found any valve that will seal in a Shimano road rim other than Shimano, which is a PITA as Shimano valves don’t have a removable core!

Are trying various bodges at the valve hole (bits of inner tube, old rubber patches etc) I found that a small dab of silicone sealant before applying the valve worked wonders…….

Happened to me every time I’ve set mine up.Extra piece of tape over top of valve hole and then nip it down with pliers but not too tight worked for me,but I’ve not done it loads of times.

Always been rim tape with me. Clean rim with methylated spirits before taping. Pull tape tight, maybe pump up tyre quite hard with inner tube and leave overnight before setting up tubeless.

Usually down to tape, but I’ve seen it where a nail punctured the tyre and straight through the rim.

It’ll be the tape not properly stuck down. Clean rim with warm soapy water and green kitchen scourer. Dry thoroughly and refit tape. Ft tube and tyre, pump up to decent pressure and leave overnight. Remove tube, and fit tubeless valve and away you go.

Or:

Fit tube
Inflate
Ride

Or:

Fit tube
Inflate
Ride

Indeed. Thing is seriously considering selling the wheels…

ouch.
Try as above inner tube to press down tape. Extra tape.

Is it (bung it in big bucket of water) leaking around the valve for definite?
I end up using a wheelbarrow to get the necessary coverage!

Sometimes valve cores can give a bit of leakage (oerr). check valve core too (less likely as you have replaced valve to be fair. Different valve type (Stans, DT Swiss).

Edit – I have found a slow leak in my rear tyre, had to pump it right up to 45psi for it to show, pinprick hole just by the bead.

I have this very problem at the moment. An ill placed stick in the spokes managed to find the gap with the valve in and ever since then it leaks. Occasionally but not all the time it leaks! Bloody infuriating. The hole for the valve is ever so slightly bent or twisted. Blob of silicone inside isn’t pretty but seems to work most of the time.

PTFE tape the valve so its a push fit through the hole.

I put an extra piece of tape over the hole for a better seal.

Cheers for the feedback. Have done extra tape over the whole, looks like I’llbe a doing an extra extra text-book super careful retape, and then try some silicon stuff. It started out as wanting to be sure the wheel was OK to sell, but now its become a challenge…

How quickly is the air coming out? Can you go for a couple of miles ride?

Have you tried shaking the wheel around to get the sealant to slosh around the valve?

I had a similar thing last year & riding it seemed to sort it.

It’ll be the tape not properly stuck down.

This might be an unpopular opinion, but in tubeless systems the rim tape adhesive’s only role is to help with installation. A tape of the correct width should end up between the tyre bead an the rim once the bead is seated, so the seal is between tape and tyre – air shouldn’t make it to the tape/rim interface.

This is why “ghetto tubeless” and Bontrager’s TLR (non-adhesive) work in the first place.

I had the same issue – a piece of gorilla tape under the valve did the trick.

My Spank rims were like this with the valves for the Nukeproof ARD inserts. I used a glueless patch over the hole for extra sealing and ended up needing to use pliers to get the lock ring tight enough it would seal.

And yes, I do carry something which would get them off if I needed to put a tube in on the trails 😁

What Dannymite says. Never needed to use the pliers tho.