[danlalan]

Originally Posted by windsurfer

Thanks guys.

The shop that I have been visiting is a reputed one and i am their customer for 3 years now. I trust they are technically good. I thought about the valve but the guy there confirmed that it was fine. Only things left out small holes which sure looks scary.

But my question is -
Why does the pressure never goes below 24? last time, i did not fill the air for 2-3 weeks. Should I leave the car for longer time?

I have got the same problem as you. Brand new tires. And in ONLY 1 tire the pressure will go down to around 24psi. All other tires will remain the same. Only difference is that instead of air i fill nitrogen.

[windsurfer]

Originally Posted by trrk

Hi,

> What should I do next?

Why don't you shift this tyre to another rim and see? This way you can isolate the problem to the tyre or the rim.

This seems worth trying. i will try this in the weekend and update you guys.

[toiingg]

Ok, i have been facing a similar situation with my tyres (all 4) but the pressure drops by about 1-2 psi in 10 days so i havent bothered much, just ensure that i check it on a weekly basis.

Initially i thought that the valve was the culprit, but got that checked and it was fine. Recently i went to my tyre wala (Minku- pretty knowledgeable chap) and he said that there is some 'Sulphur Treatment' which needs to be done on the rims(??). He said it would take max 1 hour for all four tyres.

I have never heard of such a thing.

Tyre Bhagwan... Please advise

[iraghava]

Windsurfer - Do you check your tyres at a regular interval (1 week/2 weeks) etc. or do you do a random check?? Will reply on this later once I have your response.

Also, one tubeless tyre losing pressure faster than the others can usually be attributed to the following causes:

1. Puncture - Since you're already had this checked up this is more or less ruled out.

2. Leaky valve - You've had this checked too.

3. Rusted steel rims - You have alloys, so no go here also.

4. Busted sidewalls - This is the only thing that you've not had diagnosed but this is also low probability since if it was this then the tyre would lose pressure all along & not stop at 24 psi.

Can you leave your tyres as is for a longer period of time than usual & then report the readings? Might help us more in the diagnosis.

Originally Posted by navin

"Ishan Tyrewalla" (aka Rags) advised me that this can happen with tubless tyres. Apparently small holes get created in the tyre itself and these can be repaired by your friendly neighbourhood tyre repair shop.

Originally Posted by gd1418

What exactly is this phenomena and how does this happen? How is this repaired and is there any way that this can be found while buying a tubeless tyre as this is slowly getting common.

Originally Posted by navin

I assume this happens as the tyre ages.

GD bhai this phenomena is related to age of the tyres. What happens in our conditions (all kinds of nails, screws, bolts, sharp stones. potholes etc.) is that tyres get abused more than they are usually designed for. Hence, once they start getting worn out & losing rubber they become more & more susceptible to slow punctures (this is exclusive to tubeless tyres). Now these slow punctures don't cause a loss of pressure immediately but gradually over a few days so if you check your pressure every week or so you might find a certain tyre having less pressure than the others. 95% of these cases are due to slow punctures where in many cases the puncturing object is still embedded in the tyre & thus the loss is slow.

There is not much we can do about this but to drive carefully & check our tyres regularly & get them fixed asap when necessary.

Originally Posted by tsk1979

Pump upto 50-55PSI and then check for leaks.
Even minute leaks start showing up.
And don't worry, the tire won't burst.

Originally Posted by DieselFan

Caution - 50-55 PSI might be way beyond the max. air pressure of the tyres.

50psi will not be a problem for testing at all. But do not drive around on that pressure by any means.

Originally Posted by windsurfer

But my question is -
Why does the pressure never goes below 24? last time, i did not fill the air for 2-3 weeks. Should I leave the car for longer time?

What is your normal check up interval? Leave it a bit longer than that.

Originally Posted by toiingg

Initially i thought that the valve was the culprit, but got that checked and it was fine. Recently i went to my tyre wala (Minku- pretty knowledgeable chap) and he said that there is some 'Sulphur Treatment' which needs to be done on the rims(??). He said it would take max 1 hour for all four tyres.

I have never heard of such a thing.

Tyre Bhagwan... Please advise

You have Steel rims right? What happens with them is that with age (and your car is over 8 years old) they start to rust. Now what this rust does is create small gaps on the bead of the rim where the tyre & rim join & create a seal in order to not allow air to escape. The small gaps allow the air to escape so in effect you too have a small puncture and the tyres keep losing pressure gradually.

The only ways to solve this problem are to either get the wheels sanded/filed down on the rusted parts or get new Steel/Alloy wheels.

But I would like to see pics of this "Sulphur" process. If it's anything other than sanding/filing down the rims then it would be interesting to see.

P.S. Just checked you have alloy rims. Now this sulphur process sounds even more interesting! Can you ask him to explain in details what all he does in this process & how much it'll cost? Sounds a bit fishy to me but still will check around if anyone else has heard of this process.

[windsurfer]

Guys,

I had taken my car to the same tyrewala guy. I had not checked the pressure for 2 weeks. He used the hand held pressure gauge. All the tyres showed 30 and the suspect tyre showed 29. He said that this perfectly okay. Now, I am confused. When I fill the air at petrol pump, this tyre always shows up as 24. I don't think all the pumps would be faulty. I will wait for longer now. Also, I have borrowed a pressure gauge (Bridgestone make) and would monitor regularly.

Any other suggestions?

[rks]

@windsurfer, now that you have got your own pressure gauge, check the tyre pressures when tyres are cold, say, in the morning before the car has done any running. But if you do not have a compressor handy, you have to make sure you don't let off too much air in the checking process. If you are not confident about this, take car to a nearby tyre shop and ask them to cross-check their readings with your own gauge. Usually tyre shops have more reliable gauges than bunks. If tyres are hot (which will happen when car has run for some distance), then you will not get accurate readings.

[janitha]

I too have a similar problem. My front right tyre losses 4-10 pounds every 3 days. The vehicle (Tata Vista) is one month old and I have never used tubeless tyres in the past. Pl help.

[Ravveendrra]

From the description given, the problem is caused by either a small microscopic slow puncture or a puncture with a foreign object left stuck in it.

What happens is that the hole is so small that it is difficult for the air to pass through. Air passes only when the pressure is high. Remember the old garden hose which looked like a fountain when the water is turned on full and you blocked the nozzle to get a spray.......but which did not leak much when you let the water flow freely, this tyre is something like that. When the pressure is high it leaks through the tiny puncture but when the pressure is low the hole is too small to let the air pass (rubber being elastic closes the hole to some extent).

Cheers,

[janitha]

Originally Posted by Ravveendrra

From the description given, the problem is caused by either a small microscopic slow puncture or a puncture with a foreign object left stuck in it.

What happens is that the hole is so small that it is difficult for the air to pass through. Air passes only when the pressure is high. Remember the old garden hose which looked like a fountain when the water is turned on full and you blocked the nozzle to get a spray.......but which did not leak much when you let the water flow freely, this tyre is something like that. When the pressure is high it leaks through the tiny puncture but when the pressure is low the hole is too small to let the air pass (rubber being elastic closes the hole to some extent).

Cheers,

If so, what can be done? Is there any possibility of warranty claim since it is just one month old?

[toiingg]

Originally Posted by toiingg

Ok, i have been facing a similar situation with my tyres (all 4) but the pressure drops by about 1-2 psi in 10 days so i havent bothered much, just ensure that i check it on a weekly basis.

Initially i thought that the valve was the culprit, but got that checked and it was fine. Recently i went to my tyre wala (Minku- pretty knowledgeable chap) and he said that there is some 'Sulphur Treatment' which needs to be done on the rims(??). He said it would take max 1 hour for all four tyres.

I have never heard of such a thing.

Tyre Bhagwan... Please advise

Ok, this problem of mine was solved a long time back. Thanks for reviving the thread. Time for an update.

I had gotten the rims 'serviced'. Well what they did was unmount the tyre, put the rims on the wheel balancing machine, and use sandpaper (i guess) to scrub the insides of the rims.

This did not help. The problem persisted with all 4 tyres losing 2-3 psi in a week. No punctures.

Finally i decided to get the valves changed. Got 2 changed at one time and wanted to check if it made a difference before getting the remaining 2 tyre valves changed. Well, it did work. After a week, the 2 tyres which had the new valves, did not show any loss of pressure.

Went back to the same guy and got the valves changed on the remaining 2 wheels as well. All's well.

It's been some 3 months now. Tyres not losing any pressure. Although I do make it a point to check it every 2 weeks.

Oh yes, the new valves which were put in were of some German make. Don't remember the name. Cost 100/- a pop. (i know i was overcharged, should be around 50/- each + whatever they charge for fitting. But i was so happy that the problem was rectified that I didn't care).

Cheers.

[simran]

I have the same problem with one tyre. The shop guys cleaned the alloy wheel and the tyre where it sits. He was unable to find anything wrong after immersing the tyre in water for a long time. He said the valves were fine.

I will check after a couple of weeks. Will try to replace the valve if this has not worked.

My other car has tubeless, and no such problems in 4 years. I had changed to alloys (2nd hand) mid-way in this car, and the place where I mounted the old tyres on alloys did not clean the alloy wheel or the tyre before mounting, so I am hoping this was some dirt stuck somewhere that caused a slow puncture. The valves are also old, so they might be the problem as well. I will update the thread with what happens.

Learning - clean the tyres and the wheels when mounting.

[RAC]

Friends
I drive a Reva and I have this peculiar problem with one of the tyres. But first, some info on the car and tyres.
The car has run about 46000 Kms and the tyres are probably near their end. They are not yet worn out upto the markers but probably age wise, they need replacement. However I am in no position to replace the tyres as of now and need cost effective solution. The tyre size is 145/70 R13 and the prescribed pressure for the rear tyres is 40psi and 35psi for the front

Problem: one of the rear tyres leaks out air every week and settles down at about 20psi. This is happening regularly over the last couple of months and every time the pressure at that particular tyre is 18-20psi. I am filling in air every week. I have checked the tyre for puncture and there seems to be none. Now, I have the following options:

Replacing the valve - This may or may not solve the problem.

Convert the tyre into a tube type – This means that I will need to buy tube for 2 tyres.
Now, if I go with this option, I will have 2 tubeless and 2 tube type tyres for the car. I need advice on whether to fit the tube type in the front or the rear of the car keeping in mind the recommended air pressure.

Please advice.

[sgiitk]

I have a similar problem on my Accent. After I changed over to Tubeless Tyres about two years ago I have to pump up two of the tyres every week. What I have found is that there is a very slow leak (about 1psi every two days until I am down to about 20psi) from the seat on the rim (Hyundai Alloys). I have just learnt to live with it and pump up the tyres every week or so.

[nishantgandhi]

I have faced the same problem with my tubeless tires. The problem was detected as a leaking valve. Dont ignore it. Go to a proper tire shop (not the roadside puncture guy) and ask him to check thoroughly for punctures/leaks. If no puncture, then this leaking valve has to be your criminal. Its a simple Rs 100 job.

[tsk1979]

Note from mod: Thread merged