Slow Leak

[rtrainer]

I have Cooper ST215/75R17.5 Work Series tires on Lionshead black Phoenix wheels. I also have a TireLinc TPMS. The issue that I am having is that I have a slow leak. I have put soapy water on the value and around the tire bead with no signs of a leak. There is also no weird tread wear or anything that looks like a puncture. Took the wheel off the rig, inflated it to 120PSI and let it sit overnight in the garage. Pressure dropped to 115PSI by the next day. Temperature in the garage did not change much overnight so it should not have been a factor. I did tighten the valve stem before inflating so that also should not be an issue. I attached a photo of the valve stem.


Ideas?

[Country Campers]

Does it continue to loose pressure if left for another night?

Brian

[COReflection]

I have Cooper ST215/75R17.5 Work Series tires on Lionshead black Phoenix wheels. I also have a TireLinc TPMS. The issue that I am having is that I have a slow leak. I have put soapy water on the value and around the tire bead with no signs of a leak. There is also no weird tread wear or anything that looks like a puncture. Took the wheel off the rig, inflated it to 120PSI and let it sit overnight in the garage. Pressure dropped to 115PSI by the next day. Temperature in the garage did not change much overnight so it should not have been a factor. I did tighten the valve stem before inflating so that also should not be an issue. I attached a photo of the valve stem.


Ideas?

If you have checked the tire by removing and soaking in water, checked the beads and the stem, the last thing would be a porous aluminum rim. We had a huge water bin that we could soak the wheels/tires in and check all spots for bubbles and leaks before we condemned the rims while I was working as a dealership tech many years ago.

[rtrainer]

Does it continue to loose pressure if left for another night?

Brian

It lost 1/2 lb overnight

[Country Campers]

Loosing 5 lbs the first night could be the temp of the air put into the tire as well as temp change. 1/2 lb over the second night is not too worrisome. Do you have a leak?, not sure but checking with a complete tire/wheel submersion as noted above may be the process needed next.

Brian

[Skilletface]

Replace the whole valve stem. There are plastic or silicone seals around the stem itself they swell up and contract or maybe the threads inside the valve stem are crossed.
Had a similar issue only difference was it wouldn’t leak while I was monitoring it.

[rtrainer]

Finally had some time to stick it in a tube of water. Found the the leak is in the stem core. Very, very slight but it is leaking.

This brings me to the next issue, which stem cores to buy. I figure that the ones at Advanced Auto,etc. would not work well for a 125psi tire. Looking around the internet gives a lot of results but no clear choice.

I looked at the Shrader site and the are a lot of options for air applications.

Suggestions?

[Jlawles2]

I'd probably go for https://www.napaonline.com/en/p/NTH90416 200 psi rating.

[Yoda]

Finally had some time to stick it in a tube of water. Found the the leak is in the stem core. Very, very slight but it is leaking.

This brings me to the next issue, which stem cores to buy. I figure that the ones at Advanced Auto,etc. would not work well for a 125psi tire. Looking around the internet gives a lot of results but no clear choice.

I looked at the Shrader site and the are a lot of options for air applications.

Suggestions?

Do you have a trusted tire store near you like Discount tire or Big O. They have good replacement valve cores and can offer good advice.