A few weeks ago I noticed that one my tires was consistently loosing air. Every 2 days I am loosing around 10 psi, I checked the tire and couldn't find the source of the leak. Since the tire was pretty worn I decided to have it replaced. All seemed well then 2 days later I realize the same thing is happening. I don't see any damage to the rim and I was told it the tpms type valves usually don't leak. I am at a bit of a loss, any ideas will be appreciated.

 

Just because you can't vidually see a rim break or crack doesnt mean it's fine. It will have to be inspected by an experienced pair of eyes, probably in a dunk tank. However, this is, I believe, less likely than a seal problem.

TPMS valves certainly can leak, i dont know the exact incidence rate or anything.... My TPMS was leaky and needed a seal, and i learned all about it in the process. Go to someone honest and have them look at it.

90% of the time there will be a seal that is bad on the long part, and it's cheap ($10) to fix.
10% of the time the TPMS will have another higher seal that is a problem, and Mazda's TPMS is the minority in which they are not separable and the whole thing needs to be replaced, approx $60.

 

If the tire is new its not the tire so that just leaves the wheel and valve stem. I am sure the guy who but the new tire on the wheel would have said something if the wheel was bent or damaged, but then again you never know. I am leaning towards the valve stem

 

Yeah I am thinking valve stem too...the tire was inspected before it was replaced since they knew about the problem. If the valve step seal something I can check myself?

 

The seals on the TPMS are prone to leaking.....if they didn't remove/re-install the valve and seal...it likely is still leaking like before

 

The simplest way would to either get some bubbles or water and soap mixture and put some around the vale stem to see if you get any bubbles.

 

Will check that, but what would be the procedure to actually fix the problem? Do I just need to tighten the stem or do I need to replace the seal?

 

had a similar problem over the summer.
took it to a tire place and i figured it was a nail.

10 minutes later they brought my car out and said it was a bad valve stem. and i didnt even pay a cent!

 

You must remove the tire, or at least deflate it and break the bead, to access the TPMS valve stem and replace the seal. It's a bit tricky, so be careful messing with the valve stem. Last I checked they were around $100.00 apiece. You might consider taking the wheel to a Mazda dealership since if they break the valve stem, replacement would be their expense. At least that's the theory.

 

They can leak right at where the TPMS valve passes through the rim. The "new" TPMS's seem to work better than the old, as the gasket/grommet looks better.
This leak will usually show up to be worse as the weather gets colder. It can happen anytime one is taken out and put back in, or even when bumped by someone just replacing tires. I solved mine after quite sometime by actually installing another gasket/grommet on each wheel after putting the TPMS through the rim, then installing the new grommet from the outside, and then cranking down the valve stem nut. There's a thread with pictures on what I did somewhere on this site.

Here's one link I found where it was discussed and a link to my thread is in this one, but it seems as if my thread with pictures/diagrams is no longer there.

https://www.rx8club.com/showthread.p...ight=tpms+leak

 

Interesting, the more I read about this the more I think this is my problem. Nothing has happened that could have caused damage to the wheel. But as soon as it started getting cold the problem started to get worse and worse. If I remove the valve stem nut from the outside and slip a new grommet on and replace the nut will this solve the problem? Or do I actually need to get at the TPMS sensor from inside the wheel?

 

likely the valve. had the same problem

 

I somewhat disagree Nvrfalter...............especially if it has gotten worse as the weather has gotten colder. Check back on this thread later tonight and I'll have added pictures to show you what I dealt with. All the info is on my home computer.

Forgot to look or ask the OP if he's on stock rims or aftermarket? This leak issue can really show up on aftermarket rims more so than stock.

So here is one of the write-ups and rather than link it, here it is:


Anyway....yes I was having an issue when I put the HP Evo Lightning Hyper-Darks on my car. I have since come to find out that this doesn't really have to be the HP rims, because people have seen this issue with other rims and even with stock rims.

Having said that........Mazda also changed the grommet on the rim, so if you have an 06 or newer, you probably have the improved grommet and may not have any issue at all.
My issue on my 05 was that one of the four had a leak when I moved the TPMS's over from my stock rims to the HP's. That leak was eventually was traced to the sealing grommet on the TPMS leaking. I tried another TPMS(old grommet design) and even another rim(another HP) and got the same result....a slow to medium leak.

I ended up sliding on another grommet(see that post again) on the one Rim/TPMS that was leaking. This added grommet was placed on the valve stem after it went through the rim but before putting the long valve stem nut(that holds the TPMS to the rim). So essentially had an inner and an outer grommet. As you will read in that post, I was pretty sure it would show up eventually on one of the others. Of course I procrastinated and didn't do anything about the others and they were fine for well over a year or so. This Winter(during a real cold snap down here), another decided it was going to leak.........as I figured it might eventually. I then went and put the extra grommet on all the remaining three and haven't lost any pressure in any tire since.....even through a couple of more cold snaps.

Here is the other and spells out what grommet I used.:

Okay...so now onto the TPMS. This may not be specific to these rims as I've come to find out(do some searches), but I will tell you that I had an issue in one wheel and expect to eventually have it on all wheels. I was having a leak around where the TPMS is supposed to seal to the rim. I recommend you at least read this thread, but I have the answer for you.....IF you have this issue.

https://www.rx8club.com/series-i-tech-garage-22/tpms-gasket-114960/

That first one is where you will see me discussing my issue, except for all those that helped via PM's over the month I dealt with it.

https://www.rx8club.com/nw-rx-8-forum-33/whats-wrong-discount-tire-118453/

That second thread is someone having a very similiar issue in the last week and is on stock rims, just changing tires!


Okay..............so the bottom line is................unless you have the "new" gasket TPMS's(which can be seen in that first thread), you MAY have an issue like I did. No proof the "new" TPMS's work any better to this point, but they look better! See pics in first thread!

Basically(providing you have the older style gaskets on your TPMS) I recommend a second seal. That is...........install the TPMS into the rim with the old TPMS gasket just where it is. Then slip another gasket over the threads and work it carefully down into the rim hole(from the outside of the rim), there's a lip in that rim, you will see it. Then put the big valve nut on and tighten it down. I was considering using a grommet or O-ring on mine, but then I went to Autozone and they have a perfect grommet if you will.

Ask them for Xtra Seal....metal, bolt-in tire valves. They come in a red and black box, and are 3/4" Chrome valves(part number is 17-560). They're made by Group 31 who ever the hell that is. I bought a box of ten cause they were cheap, but you only really need four, since it's the gaskets or grommets you are after.

Here's the one you are after........spin the two nuts off the valve, then remove the next metal piece(a spacer?), then you will see the two gaskets. You don't want the first one, but take that second one that looks like a "T"(from the side)...........for lack of a better description. This is the one you want to put onto the TPMS's after inserting the TPMS through the rim. I would put the narrow end in first thereby having the top of the "T" to the outside, whereby the valve nut supplied with the TPMS would then create a seal between this and the lip inside the rim. Basically, the two gaskets(the original from the inside and the "new" from the outside) will meet at the lip inside the rim. Make sense?

Anyway...........I only had to do this with one wheel as the others are fine, but I figure that I might have to do those eventually as well. That's why I bought the box of valves. I watch them closely because I figure they can leak at a moments notice.

To solve this friggin puzzle, I actually went through two TPMS on that wheel, and Jeff at Wheelfire was gracious enough to send me another rim because we though it was the rim at one time. Yeah, I now have an extra rim! Oh yeah...............and two different tire shops couldn't figure this out, so I finally took matters into my own hands and got it solved. Jeez!

Hope this helps, I know it was long.........I should make a more condensed version and make it a sticky one day. I'm sure a lot of after market rims will have this issue and I'm sure from reading...that even some stock ones do after changing tires. Basically the TPMS gasket sucks. The new one may be better.

JSMITH.......I have a bunch of these extra grommets, so if you just want to try a couple and see, I'll gladly send you a couple so you may try it. All I need is your postal address.

EDIT: Below is a rough drawing. The yellow would be the grommet I put in myself.

 

Thanks for all the info, I have not had a chance to work on it yet. I will take my car to the dealership one more time and give them another shot (3rd trip now). If they don't get it sorted this time it's 3 strikes you're out and it will be DIY time for me!