Tyre deflation issue on Gunbarrel - advice

I know nothing about tyres, other than you need them to get some where, but from what you have said "tyres are 6 years old" and "looked like the punctures were very small cracks" i would say the tyres are starting to perish.
baz

Classis symptoms of tyres too old and past their use-by date. Í think I've read somewhere that after 4 years you should consider disposal. You did well to get 6.

Cheers

Hi Boobook
i travell in the area.
On the gunbarrell east of Carnegie i drove over some very sharp shale almost like broken tiles,i wast was only a few feet of this.i immediately got a pucture,and while changing it i noticed the other tyre was hissing.2 punctures at the same time is unusual.
could have been this,especially as when its been graded it can be worse.

Tyre will deteriorate with age. They become brittle and crack. This is especially if you live in a hot climate like I do in the top end. I do not expect to get more then 5 years out of a tyre. When you buy a tyre check the date of manufacture. Sometimes they may be stored with the dealer and the 5 years is from the date of manufacture, not date of purchase.

You sound a bit bewildered as to why it happened well having low km on them is irrelevant you could buy a new set leave them in the shed for 6 yrs or so then fit them and they will be at a high risk of getting punctured etc because they are perishing with age. So it's just one of those expenses you have to live with if you want to increase your chances of get back safely when travelling off road.

I've had the same thing happen twice before following multiple trips on the Gunbarrel and Anne Beadell highways. Took one to a tyre dealer back home and they couldn't find any source for the leak inside the casing, so simply put a tube in it. That tyre was a D694, about 6 years old and had done about 70,000k but still had plenty of tread. Second example was an MTR which subsequently developed a slight bulge so it was assumed to have delaminated, so was scrapped after 45000k.

Thi Boobook

Just off topic.....how did you find those charming corrugations north of Neale Junction on the CS.?

I can not believe how bad they have become within 4 years and I now believe worse that the ones east of Emu on the Anne Beadel.



Cheers




Stephen

Hi Boobook
Could it have been from stone impact? I had a similar issue where the tow rig was throwing up stones and they were impacting on the face of the tyre on trailer.
I had this on the Oodnadatta track when I didn't have adequate stone protection.
This can also account for why your rear tyres get more punctures than fronts. Front tyres can be succeptable to flats as they are the first to run over things.

Sure as hell sounds like general carcase deterioration. It might just be that the reasonable service life for those particular MT's is up. As an example, I'm doing annual hub maintenance on my van at present.....the 265 x 16 BFG AT tires would have to have been manufactured 7 years back, minimum - they've done about 65k (maybe 10k on gravel). On the first wheel I just took off and cleaned thoroughly, the tyre overall shows no rubber deterioration at all...just tread loss. I'm paying close attention, because some Cooper AT's that I took off my 100 series a few years back (6 years service) had 30% tread remaining, but small cracks were appearing all over the place (and chipping badly too). Probably a bit of a lottery - I went Cooper ST for my second set on the car and they were great. Even with BFG, they have two different manufacturing plants....maybe that matters. And while softer tyres grip better, but wear sooner, harder tyres last but crack and chip sooner (I'm told). Seems Mickey is owned / made by Coopers anyway.....and Cooper have lots of manufacturing plants worldwide......Michelin own BFG (tires only) too.....sigh.

Across the tyre industry there is a general rule that tyre from 5 years onwards are not for sale and should be scrapped. This is simply as previously described tyres get old and fracture. The comment about putting tyres in the shed for curing is not correct with regard to modern rubbery and composite compounds. Modern tyres actually don't have a lot of what folk would call "rubber" in them these days. They are a chemical cocktail with composite fibres and stainless steel wires and glues moulded together to form the tyre. This link explains the issues https://www.jaxtyres.com.au/tyre-age.

The matter of tyre age is particularly important when considering spare tyres which are rarely rotated and so never get any use so prematurely expire. Hence it is a good idea to rotate all five tyres

Rob

What speed / pressure / loads were the tyres subjected to?
Could well be sidewall break down from excessive heat due to too high a speed/too low a pressure. This can wreck any tyre in very quick time.

Cheers,
Peter

Boobook
I had the same thoughts as Peter, what speed were you traveling at? I think that is more often than not the cause of many punctures, not tyre age.

I drove over that section of the Gunbarrell two years ago on tyres that were eight years old without any problems. I still have them and they will be back in the bush again tomorrow. We were driving at very low speeds though. I have spent many a day on steep and very rough rock covered mountain tracks at not much more than walking speed. You don't have any choice in those conditions but I can do it all day on desert tracks as well if I have to. It all depends on the conditions.

I have heard many people say it is harder to burst a deflated balloon with a pin than it is to burst a fully inflated one. This is usually given as the main reason for deflating tyres on Outback roads or tracks. That may be true but try puncturing a tyre with a pointed rifle bullet by holding the bullet and stabbing the tyre by hand. You would have no hope but the bullet would pass through easily if you fired it out of a gun. The only difference is it is traveling much faster. I think the same applies to driving over sharp rocks at high speeds.

I have only destroyed old tyres once and that was on a trailer. I built a motorcycle trailer in WA in 1973 with second hand Mini wheels and tyres. I towed it back to Sydney over a then unsealed 400 or so kilometre section of the Eyre Hwy.

I then added a bolt on 6x4 steel box and used it regularly. I blew both tyres with the trailer overloaded on the Hume Hwy near Bowral south of Sydney in 1989. The tyres may have been close to twenty years old.

The now ten year old tyres on my 4x4 are standard size 205 x16 LT. The pressures listed in the owner's hand book are so low that I do not deflate them no matter where I go. If I had a bigger car like a Cruiser or Patrol, I would be using a 7.50 x16 and would use them the same way. These tyres have the added advantage of missing a lot of rocks or pieces of wood that would penetrate the sidewall of many of the popular wider tyres.

Boobook - You fail to state your tyre pressures at the time. If you were running low pressures to reduce shock and damage to the camper, it's likely that the tyre sidewalls are bulging excessively, and sharp flinty rocks or pieces of bush timber have almost, but not quite, totally penetrated the sidewall.

Wood from bushes and trees in the interior is very hard, almost like steel, when sun-dried. Pieces of broken wood get pulled into the road formation with graders, and you can get tyre stakes from this wood, particularly after grading.

On roads and tracks that are rarely graded, sticks from trees and bushes at the track edge that are hit by passing vehicles, leave hardened pieces of wood on the wheel tracks, that make good tyre stakes.
These broken sticks flick up when the vehicle passes over them, and the camper or trailer tyres meet a sharp projection that is angled towards the tyre, and a tyre stake is the result.

All tyre manufacturers have recommended minimum inflation pressures, and they should not be disregarded - despite many 4WD'ers saying you must deflate tyres to low pressures on corrugated roads, to improve the ride.

I'd have to say the rock or stake damage has been enough to tear the rubber, but not fully penetrate the tyre, resulting in a tiny hole that is now leaking.

Despite tyre manufacturers recommending 6 yrs as the life of modern tyres, most tyres will perform satisfactorily for 10 and even 12 years, provided they are not in the harsh sun constantly.

Manufacturers have to set a limit on tyre life - and of course, they are going to err on the lower age limit side, simply because they want you to scrap perfectly good tyres and buy new ones!

They have no way of knowing the conditions the tyres are used under, so they have to adopt "worst-case scenarios" (i.e. - in the hot sun constantly, regularly run at wrong pressures, overloaded and generally abused), to set the tyres recommended life.
I have even seen tyre dealers telling people that they needed to scrap low-age tyres that had 30% tread left, as the tyres no longer had the same grip as new ones!

Cheers, Ron.

This has caused me distress since I have just realized my caravan tyres must m
Be 10 years old.
Never thought about this, guess I should get some new ones.

I don't believe Michelin place any age restrictions on their tyres.

Cheers,
Peter

Hmm, It seems by the range of answers my problems were definitely caused by old age or not, or wrong speed or not, or wrong tyre pressure or not, or normal punctures or not.

Oh well.

Given identical failures and symptoms on different days with tine holes and absolutely no sign of something having been in the tyres, I am running with the old age theory.

Thanks everybody.

Ok, so now we are all going to chuck our tyres after 5 yeras.

Have you looked up your tyre manufacturers data?
Coopers are good to around 10 years age when they recommend you scrap them. I think 10 years is pretty standard and 5 years would limit sales a bit.
http://us.coopertire.com/Tire-Safety/Replacement-Tire-Guide/Tire-Service-Life.aspx

Obviously the replacement age depends on a lot of variables but arbitrarily tossing them at 5 years seems a bit silly.