Tyre valves leaking?

Slipperyeel

Well-known member
UKGSer Subscriber
Joined
Jul 8, 2012
Messages
2,985
Reaction score
20
Location
London
Looking for some thoughts.

I've got a slow leak on my front tyre. I've had new tyres since last July (conti TA3s).

Thought maybe I had a slower puncture in the front. But I've made two separate hard looks at the tyre and it looks just fine. It takes about a day or so to lose a few single- but enough to need a top up.

So, my suspicion is with the valve itself. My bike has TPMS so the valves are slightly different.

See pic attached. Is it possible there it's an O-ring or something in the valve 'insert'?

Thanks for feedback



Sent from my SM-G975F using Tapatalk
View attachment 435123
 

Attachments

  • 20200112_112310.jpg
    20200112_112310.jpg
    45.3 KB · Views: 402
try spraying some water on the valve and see if it bubbles

I had something similar and just tightened the valve slightly and problem fixed. but might be something else in yout case
 
try spraying some water on the valve and see if it bubbles

I had something similar and just tightened the valve slightly and problem fixed. but might be something else in yout case
I'll give it a go. But it's so slow I'm not sure if it'll generate a bubble?

When you tightened yours, am I right in guessing you held the larger 'nut' section and turned the thread 'valve' part? I'm kinda hoping/ expecting it is something just like tightening that'll do it.



Sent from my SM-G975F using Tapatalk
 
The hex part is a sleeve over the threaded valve part which is fixed to the pressure transmitter body. The hex sleeve is loctited onto the valve part. Don't disturb it unless you know there is a leak there. Try soapy water and high pressure (80psi)...
 
The hex part is a sleeve over the threaded valve part which is fixed to the pressure transmitter body. The hex sleeve is loctited onto the valve part. Don't disturb it unless you know there is a leak there. Try soapy water and high pressure (80psi)...
Didn't think if raising the pressure
Good idea . Thanks

I'm going to try that. Thanks to for warning on that valve arrangement

Sent from my SM-G975F using Tapatalk
 
Here is what they look like, note goop on the larger thread. I got a new one to replace this one but it did not come with the hex sleeve nut. Tyre man told me he had a tough time cleaning the sleeve fit to reuse..
 

Attachments

  • TPMS.JPG
    TPMS.JPG
    94.8 KB · Views: 315
Here is what they look like, note goop on the larger thread. I got a new one to replace this one but it did not come with the hex sleeve nut. Tyre man told me he had a tough time cleaning the sleeve fit to reuse..
That's really helpful. Thank you

I have a better idea of what's connected to what.

I can see then, that there are two possible leakage points. 1. The valve innards- easy enough to fix. 2. The seal between the the sensor and the rim ie. Between that hex sleeve and the rim...

I'm going to try the over pressure test as that should reveal a lot quite quickly (and test my little pump!). I'll go from there and report back.

Sent from my SM-G975F using Tapatalk
 
Another update. The lockdown is proving useful

A week or two ago I wheeled out the moto to give a reasonable clean up after all the work that's been done (steering bearings, both shocks out for rebuild by Luke and some other stuff).

While cleaning, I caught it! Found the leak that I think I've now solved.

Would like some advice on how tight I can go with the spanner in that valve housing? Or is it better to get the tyre off?

Couples of vids here...

Found leak: https://youtu.be/ZTOXEzK7zEE
Tightening up: https://youtu.be/kCRAEk5rvOc

Sent from my SM-G975F using Tapatalk
 
try spraying some water on the valve and see if it bubbles

I had something similar and just tightened the valve slightly and problem fixed. but might be something else in yout case

Not by a lot. I nipped it up and re-checked with water and fairly liquid
 
I recently replaced the battery in my rear tyre pressure sensor. When refitting the valve/sensor assembly I checked the hole in the tyre was good and clean and wiped it down with brake cleaner spray. I also checked the seal on the valve post was good (it was) and put some Vaseline on it so it would ease in nicely (red rubber grease would have been better but the remains of my pot is very skanky) and tightened the collar by hand. It went from being an easy turn to tight in about 1/8th turn. I then just nipped it maybe less than 1/16th turn with a 12mm spanner on the basis it was better to have it a bit loose so I could tighten it up rather than too tight and damage the seal. But tbh it didn’t feel it would tighten much more, you know like the threads were bottomed out anyway. It has been fine in the garage so far. No leaks.
 
I checked the hole in the tyre was good and clean and wiped it down with brake cleaner spray.

Not sure you are inflating correctly if doing so via hole in tyre :stupid

On a seriosu note though, lubricating the threads may not be best idea. a tiny dab of low strength (ie purple) threadlock on reassembly after batts might stop it vibrating loose
 
Motorworks do a rebuild kit. New sleeve nut, rubber seal and valve cap.

I had a leak like you have on rear wheel, when stripped down it turned out there was slight corrosion on the rim, all cleaned up, rebuilt with the mototworks kit, job done.

Roger
 
Motorworks do a rebuild kit. New sleeve nut, rubber seal and valve cap.

I had a leak like you have on rear wheel, when stripped down it turned out there was slight corrosion on the rim, all cleaned up, rebuilt with the mototworks kit, job done.

Roger
Interesting. Thanks. I'll take a look at MW. Totally unaware there is such a kit

Sent from my SM-G975F using Tapatalk
 
From 2008 GS manual
Blimey. Never seen that before. I do actually have some metal various with a rubber seal in them. Never thought of this and I guess it makes some sense. Will get the metal caps it!!

Sent from my SM-G975F using Tapatalk
 
I recently replaced the battery in my rear tyre pressure sensor. When refitting the valve/sensor assembly I checked the hole in the tyre was good and clean and wiped it down with brake cleaner spray. I also checked the seal on the valve post was good (it was) and put some Vaseline on it so it would ease in nicely (red rubber grease would have been better but the remains of my pot is very skanky) and tightened the collar by hand. It went from being an easy turn to tight in about 1/8th turn. I then just nipped it maybe less than 1/16th turn with a 12mm spanner on the basis it was better to have it a bit loose so I could tighten it up rather than too tight and damage the seal. But tbh it didn’t feel it would tighten much more, you know like the threads were bottomed out anyway. It has been fine in the garage so far. No leaks.
Thanks. You've given me confidence to give it more of a tighten. Now wondering why it's quite so lose at all? I mean I've given it the total of about 1/2 a turn already, and it moved easily with the spanner.

I'm wondering if the guy did something at the last tyre change... He always bleats on about hating tpms and how difficult it is to change tyres with them fitted. I'm wondering if he deliberately unscrewed it, to get it clear when he removed the tyre?

Sent from my SM-G975F using Tapatalk
 


Back
Top Bottom