[sivadas]

When I was checking Tyre pressure at Shell petrol bunk (some 2 months back), I suddenly noticed that rear right tyre alone was showing less pressure (17psi instead of 30). I thought it to be a misake as I always check the tyres before start driving. More over, with so much pressure difference, I should have seen the tyre flattened. After this I was constantly watching this tyre and it always appeared(!) normal. During next fill, again it was noticed that pressure has come down to 24psi for the same tyre. After this I did a trip to Hoggenakal (some 180Kms from Bangalore)and came back, again checked the pressure, it is down to 24psi again. This time I didn't want to take chance, replaceed the tyre with the spare one and gave the culprit to nearest tyre repairer. Surprise! (Really?) Within seconds he pulled out a very small nail from the tyre.
Now, you guys will tell that it is very basic, I should have done it first time(or at least second time) itself when noticed that pressure is reducing. Yes, I totally agree! But I was expecting some visual clue or impact to ride when there is a drop in pressure which didn't happen in these cases.

Lessons learned:
1. Better to check the tyres for puncture even if there is a drop of 1 or 2Psi
2. Must check the tyres for puncture (if there is a drop of 1 or 2Psi) before going for any long trip
3. Tubeless tyres are just great

Your comments please.

By the way, my tyres are 195/60/R14 Potenza GIII and car is Fiat Petra.

[Vid6639]

thank you sivadas. that means my turanza front left has a puncture since it always drops down more than the other 3 every 2 weeks. I fill 30psi after 2 weeks 3 of them show 27-28psi whereas the front left is 21-24psi.

[speedzak]

I took our Accord to the service station when I was faced with a similar situation. Tyre pressure drops very little (4-5 psi) everytime it's taken for a pressure check. The valve turned out to be the culprit.

In a similar scenario of my Alto rear Tyre, it was a nail. And the pressure drop used to be huge (17 in place of 30). A puncture can cause big drops in pressure, but if it is just a psi or two drop, then not necessary to get checked for puncture.

[suman]

Its been happening regularly with my Safari for the past month or so. Rear right tyre pressure drops more than the other three. Yet, had this checked out at no less than THREE different pumps and all agreed there was no puncture or valve problem........

One of these days, I'll open up the tube irrespective and check it out I think. I've been dilly-dallying because I don't want to unnecessarily expose the alloys to mechanical tyre removal (most of the repair shops I've checked out do not have the machine removal set for 16 inchers)

[kpzen]

Thanks for sharing.!!! It could be helpful to many here..!!

The problem is that in tubeless n radial tyres the air pressure is difficult to judge visually. There's every chance of getting it wrong.....

[icemanz]

1-2 psi drop over a week is normal. A difference of over 5psi should raise the alarm.
Once a week air pressure check should be practiced, lower than recommended psi levels impacts your FE.

[theMAG]

Originally Posted by suman

Its been happening regularly with my Safari for the past month or so. Rear right tyre pressure drops more than the other three. Yet, had this checked out at no less than THREE different pumps and all agreed there was no puncture or valve problem........

One of these days, I'll open up the tube irrespective and check it out I think. I've been dilly-dallying because I don't want to unnecessarily expose the alloys to mechanical tyre removal (most of the repair shops I've checked out do not have the machine removal set for 16 inchers)

If your's is a tubed tyre the tube might have gone weak.

[suman]

Originally Posted by theMAG

If your's is a tubed tyre the tube might have gone weak.

Jeez, in a 5 month car that's just about nudging 10k kms???? In any case, can't figure out why the valve is not showing the "weak"ness, normally, it would show bubbles when they use the good old saliva test.......

[yogi1771]

hi suman even i had the same probs in my fiesta mrf tyres(piece of crap),had it checked in four different places even had the valve pin replaced but the problem persisted finally changed the valve and now everything is fine

[GTO]

Tubeless tyres conceal a leak very well.

[iraghava]

Originally Posted by suman

One of these days, I'll open up the tube irrespective and check it out I think. I've been dilly-dallying because I don't want to unnecessarily expose the alloys to mechanical tyre removal (most of the repair shops I've checked out do not have the machine removal set for 16 inchers)

Need the address of a shop which can deal with 16 inchers?

Originally Posted by GTO

Tubeless tyres conceal a leak very well.

Yup, if filled up regularly they can actually go on for months. A couple of years back I drove on a tyre for more than 2 months while it had 4 nails embedded in it. Regularly filled up air & it continued to work just fine until one day I got the time to get it repaired.

[rks]

Tyre pressures need to be checked in cold condition, preferrably first thing in the morning. And an accurate gauge (digital or analog) is necessary. I check every two weeks and I find virtually no change in tyre pressures.

Also daily visual inspections for nails are very important in the case of tubeless tyres. I have caught two nails/screws in my tyres (which didn't cause a noticeable drop in pressure) in the first 11000 kms with tubeless tyres, both times in my own parking area on or a day before I left for Mumbai. Even when I had tubed tyres, on two occasions I found half-inch bent nails gone in and fortunately no puncture was found. Better to drive to the tyre shop of your choice and get the puncture fixed rather than face an emergency in some desolate spot (and possible damage to your tyre/wheel if you run flat for a considerable distance).

[kpzen]

Originally Posted by iraghava

Yup, if filled up regularly they can actually go on for months. A couple of years back I drove on a tyre for more than 2 months while it had 4 nails embedded in it. Regularly filled up air & it continued to work just fine until one day I got the time to get it repaired.

provided u have alloys for tubeless tyres.....

Steel rims + tubeless tyres tends to cause more leakage as compared to tubeles + Alloys..

[iraghava]

Originally Posted by kpzen

provided u have alloys for tubeless tyres.....

Last time I checked I had alloys & tubeless tyres, will check again & get back to you

[esteem_lover]

This is a very good piece of information. I think the thread should be renamed as Interesting Tyre Fact.
cheers