Tyre pressure

[Drover]

So I started the big lap today and set my cold tyre pressure to 43 kpa before I left van towed really well when we pulled over for a rest I checked them hot and it was 49 kpa is that telling me I need to put more in or take some out?

Assume you mean psi ??????? 49 kpa is only 7 psi so I would say you mean psi, then if it follows well, doesn't seem to drag, a sudden wheel movement and it follows without wallowing then your pressure is probably good, tyre pressure will rise when they get hot and this is normal don't drop your pressure. if they climb to 10psi then drop a few pounds out as it's probably a damn hot day/road, over 40c usually get a big rise in pressure.
When you stop always feel the hub/drum if it burns your fingers, time to check bearings/brakes, tyres should always feel warm.

 

[Bellbirdweb]

Nitrogen does not leach through the rubber so doesn't need refilling as often as air, however if you are constantly moving pressures up and down for road to off road, it would cost you a fortune.

Air works perfectly well.

I run 40psi on road and 28 or less off road, with an appropriate reduction in speed off road to 80k max.

I also run a TPMS to monitor the pressure and temperature of all 5 tyres on the van and the 6 on the tug.

 

[Drover]

Agree with @Bellbirdweb , at least with 4 tyres you can spread the load better than a single axle and used Nitrogen in the Truck but found it was an expensive novelty really, if you wanted to stay true to the formula you had to find somewhere with a unit when away from home and I never found any benefit in the real world, sounded good on paper or the race track.

 

[Meanderthals]

So if Oxygen molecules leak out and Nitrogen ones don't then in theory by replenishing with normal 75/25 natural mix then gradually you will re-achieve a near perfect Nitrogen filled tyre, Wouldn't you?
But this can't be true and I must be wrong somewhere, because if it were true then you could achieve just a Nitrogen filled tyre for free and there would be no need to pay someone for it. That can't be true because that would infer that commercially there is a possible rip-off going on and I can't imagine that a commercial enterprise would charge you for something that you didn't need, Right?
My head hurts and I'm stressed by it. Where's the Valium and Panadol.
In 40+ years I've never had a tyre go flat unless there was a hole in it somewhere that was somewhat larger than a Nitrogen molecule. But then again in all those years I've never had a wheel come off or the nuts loosen off on cars and for most of that time I've used anti-seize that is supposed to be a no no, so what would I know.

 

[Drover]

Bahahahah @PhilD , thats classic.......I've lost a set of duals off a truck once, only 4kms from workshop.

 

[Meanderthals]

Bahahahah @PhilD , thats classic.......I've lost a set of duals off a truck once, only 4kms from workshop.

My nuts have only ever been too tight, never too loose.

 

[Angus]

Compliance plate should be used as a guide, it's a guess really. Check the load rating of the tyre fitted, check the weight of your van,not what the plate says, make sure the tyre is load rated for your rig, using the tyre load rating and the van weight you should have a figure as to what your tyre pressure should be and this would normally be at least 55psi on a single axle. Cold to running pressure diff is ball park figure at 4 psi not 4 kpa. If your running the highway with a 2t rig under 50 psi you are looking at wear, handling and other problems.
Tyres as fitted to my rig only just made the weight rating, the ones I fitted exceed the weight of my van comfortably, I don't like running at the max setting.
Bob Jane T Mart site has a handy load rating chart, check it out.
Remember most dealers are salesmen and pass on hearsay....................................

Hi drover I had the PSI/KPA around the wrong way just a matter of habit as I had been working with pressures in KPA lately at work. I have decided for the next leg to dubbo I will go to the maximum cold tyre pressure of 44PSI

 

[Drover]

@Angus, I thought as much, I'm refering to single axle pressures mostly. I found a chart that showed the psi you should have for weight/tyre size/single/dual wheel etc, should see if I can find it again.
My tyres being single have to handle near a Ton each where if I had 4 tyres then 500kg each would be fine and I could run a lot less pressure.

This isn't the list I was looking for though.

 

[Bellbirdweb]

I have a TPMS (tyre pressure monitoring system) on the tug which has been monitoring the 6 tyres (4 on the road and 2 spares)

Just ordered 5 more sensors for the van and fitted them yesterday.

Can now monitor pressure and temperature on both tug and panda.

Having had quite a few tyre issues over the years, it's nice to see what they are all doing.

The temperature can also warn you of you start getting a hot bearing, hopefully allowing you to stop before a catastrophic failure.

 

[relgate]

What TPMS do you have @Bellbirdweb ?

Ive been thinking of getting a system

 

[Bellbirdweb]

@relgate I got it on eBay http://www.ebay.com.au/itm/141243689168

Can monitor up to 23 tyres and can attach and detach the trailer

Pretty good for the price

 

[relgate]

@relgate I got it on eBay http://www.ebay.com.au/itm/141243689168

Can monitor up to 23 tyres and can attach and detach the trailer

Pretty good for the price

Great. Any hassles installing the sensors? Did it cost much or did you Diy?
What happens when you rotate the tyres?

 

[Bellbirdweb]

@relgate the sensors I originally purchased were the internal ones as shown in the ebay link.

I chose those as I had an earlier model prior that used the same system, and I wasn't too sure about the cap mounted sensors for off road/theft.

They required fitting by a tyre fitter, which I had them do when I purchased a new set of tyres. They charged me $20 per tyre to fit and balance the spare tyres.

The unit has a tyre rotation feature that allows you to rotate the tyres so they match up on e LCD screen.

For the panda, I purchased the screw on cap mounted sensors for $40 each and they were much easier to fit, no tyre fitters needed, and obviously to rotate tyres it's just a matter of moving the sensors around.

If I was starting from scratch again, I'd get all external sensors. In fact it was cheaper for me to buy a complete 2nd unit with external sensors than to buy the sensors by themselves to add to my system.

This was the 2nd one I purchased. Giving the spare control head to a mate. http://www.ebay.com.au/itm/161358338456

 

[relgate]

@relgate the sensors I originally purchased were the internal ones as shown in the ebay link.

I chose those as I had an earlier model prior that used the same system, and I wasn't too sure about the cap mounted sensors for off road/theft.

They required fitting by a tyre fitter, which I had them do when I purchased a new set of tyres. They charged me $20 per tyre to fit and balance the spare tyres.

The unit has a tyre rotation feature that allows you to rotate the tyres so they match up on e LCD screen.

For the panda, I purchased the screw on cap mounted sensors for $40 each and they were much easier to fit, no tyre fitters needed, and obviously to rotate tyres it's just a matter of moving the sensors around.

If I was starting from scratch again, I'd get all external sensors. In fact it was cheaper for me to buy a complete 2nd unit with external sensors than to buy the sensors by themselves to add to my system.

This was the 2nd one I purchased. Giving the spare control head to a mate. http://www.ebay.com.au/itm/161358338456

All good info. Thanks for the heads up. Was thinking internal sensors but was worried about ongoing costs and hassle. Seems it mught be easier and cheaper to go external and replace individually if they fail

 

[relgate]

@Bellbirdweb , where did you get the extra sensors?
Thanks

 

[Bellbirdweb]

@relgate I just emailed the eBay seller and they sold them to me separately.