Tyre Pressure Gauge

iana · Guru

Tyre Pressure Gauge

Possum3 · Guru

Ian,
Pump your tyres at an electronic gauge at local Coles Express then check immediately with your inflator gauge - Don't drive home to re-check as tyres will heat up more and pressure will differ.

Coles have their gauges checked weekly.

kezngaz · Senior Member

Didnt know that about Coles, cheers Possum3.
Kezngaz.

Kev Pearce · Senior Member

Thank you. I too worry about the accuracy of my tyre pressure gauges; and often often wondered how accurate the gauges were at "service stations" and petrol outlets. ill keep in mind the info re Coles.

Kebbin · Guru

Possum3 wrote:
Ian,
Pump your tyres at an electronic gauge at local Coles Express then check immediately with your inflator gauge - Don't drive home to re-check as tyres will heat up more and pressure will differ.

Coles have their gauges checked weekly.

Could you elaborate on the 'Coles have their gauges checked weekly' please Collin, do you mean calibrate or they check the hose and fittings? As I'm just as suspious of the electronic air stations sometimes as the cheap pocket gauges. Thanks

Dougwe · Chief one feather

Tyre pressures are a very interesting subject indeed. I have only recently gone through an exercise of trying different pressures mainly on my Collie. I have found without the aluminium tee pee on the back and a few heavier items taken out from the back of the Collie I run with 45psi on the back and 40psi on the front. With the items back in and tee pee on back I run with 50psi on back and still 40psi on front. Both vehicles are nice and level all way through when hooked up. I also don't use WDH. ALL WORKS FOR ME.

Now, during the week just gone I had a full tyre rotation, balance and front end alignment at a tyre place that say they specialise in 4x4's and similar size vehicles. The bloke doing the job came in to the waiting room and asked what pressures I run with so told him what they were as the Collie was at the time and when loaded etc. He said that was high. I asked what he thought. His words were "I run my Dmax on 32psi with nothing hooked up and with a big boat on back 35psi all round". I asked if he could do 'MY' pressures on the Collie please. "No problem mate". He didn't go any further with our chat.

If I was to run with 32psi or 35psi my tyres would be very bulgy indeed. Probably look like the Michilin Man.

Oh! I run 50psi on the aluminium tee pee.

I am aware the the adjustmets needed for gravel and sand like roads for any length of time.

I use a digital pressure guage or the Coles pumps when I can. I haven't noticed any difference between the digital or Coles to be honest but will check next time.

Keep Safe on the roads and out there.

Edit...Forgot to say, good subject Ian and in the right place too, well done.

-- Edited by Dougwe on Saturday 20th of May 2017 11:10:01 AM

rockylizard · Guru

Gday...

I won't go into the actual pressures I run in my vehicle or van. However, I understand the problem in just WHICH gauge is the 'accurate' one.

Some years ago (more than I really want to remember hmm ) I made a decision.

I determine the 'best' pressure in the tyres by 'experiment'. My first decision is to add 2PSI to whatever the manufacturer states as their 'recommendation' for the pressure for either loaded or unloaded - towing or not towing.

I have one of these type tyre pressure gauges -

Tyre Gauge.JPG

Mine goes upto 150PSI so I figure that pressures around 40>60PSI are a small percentage of its capabilities and lessen the chance of inaccuracies.

I have found that these gauges have less 'pressure' variations over time. I have had the current one for at least 10 years.

I use this gauge for the ACTUAL pressures I run in my tyres. I observe tyre wear and road 'feel' over a couple hundred Km's.

If I pump tyres with ANY other gauge - eg servo - then I check the pressure the tyre ACTUALLY has with my gauge.

Whether I am right or wrong, foolish or sensible, that is OK. I never trust any servo.

Cheers - John

Tony Bev · Guru

Edit to say, that to the best of my knowledge, there is nowhere to calibrate a normal, off the shelf, pneumatic tyre pressure gauge

I have four gauges, 2 electric, and two dial gauges

None of the gauges read exactly the same, but they are all within 3 PSI

Just remember that when you check with the first gauge, there is always the chance, (if you are a bit hard of hearing like almost 50% of us over 65's), that you may have let some air escape

I remember reading many years ago, that someone like the RAC, said that all service stations should calibrate their air pressure gauges, as many motorists tyres were over, or under inflated

Service stations said that if it became law, they would have to charge their customers, each time they used the tyre gauge

As Possum3 has already said, the tyre will be showing a higher pressure, when it is hot

-- Edited by Tony Bev on Saturday 20th of May 2017 12:31:05 PM

Mike Harding · Guru

Two interesting links:

https://en.wikipedia.org/wiki/Cold_inflation_pressure

http://www.tyresizecalculator.com/tyres/tyre-pressure-in-the-summer

Possum3 · Guru

Kebbin, Our local Coles Express has a Coles branded service/man-van come and check. I have seen him there a couple of times, I asked him when he was there servicing their digital tyre pump and he said they all have to be checked as it's Coles policy. I suppose that there are times they do a tick and flick on their sheets, but it's a matter of "who do you trust?"

The Belmont Bear · Guru

I reckon one of the best things that I have bought is the 18V Ryobi cordless inflator which only cost $99 from Bunnings due to the fact I already had a charger and batteries for it (all Ryobi one + tools use the same). You connect it and it gives the current pressure, enter in the pressure that you want either in KPA or PSI hit the button and it will cut out a little bit above that value to allow for the losses when disconnecting. Comes with attachments to do things like air mattresses, footballs etc. also includes adapters for different size valve stems. I've checked the pressures using a manual gauge that I previously purchased from Repco and they seem to consistently read within 1 or 2 PSI of each other - which one is the most accurate I don't know. To tell you the truth if I use it to inflate my rear tyres to 42PSI and due to it's inaccuracy that's more like 40 or 44PSI I don't really care as long as it's the same pressure each time I do it as that is the reading on that machine that gives me the desired result.

-- Edited by The Belmont Bear on Saturday 20th of May 2017 03:00:04 PM

rockylizard · Guru

The Belmont Bear wrote:
I reckon one of the best things that I have bought is the 18V Ryobi cordless inflator which only cost $99 from Bunnings due to the fact I already had a charger and batteries for it (all Ryobi one + tools use the same). You connect it and it gives the current pressure, enter in the pressure that you want either in KPA or PSI hit the button and it will cut out a little bit above that value to allow for the losses when disconnecting. Comes with attachments to do things like air mattresses, footballs etc. also includes adapters for different size valve stems. I've checked the pressures using a manual gauge that I previously purchased from Repco and they seem to consistently read within 1 or 2 PSI of each other - which one is the most accurate I don't know. To tell you the truth if I use it to inflate my rear tyres to 42PSI and due to it's inaccuracy that's more like 40 or 44PSI I don't really care as long as it's the same pressure each time I do it as that is the reading on that machine that gives me the desired result.

Gday...

TA BB ... you said in one sentence what I took half a page trying to say before

As I said, if the tyres are wearing properly/consistently/evenly and the road 'feel' is spot on ... that's all that really matters to me.

Cheers - John

iana · Guru

Can get the tire inflator checked at our hydraulic shop.

Woody n Sue · Guru

Ok I will ad this question has anyone with the on car preasure readout on the dash tested their preasure number against a manual gauge for any variance in readout

Woody

macka17 · Guru

D-Max.
I run 32 fr and back driving round.

As Do Di's Honda Civic. and the 2 Patrols. Navara, and Fairlanes I ran.

Up to 35 rears with van on. 32 on van (4 wheels) All 16in rims.)

At least.with the electronic pressure stations. Coles or otherwise.
You KNOW. you getting ALL tyres the same pressure.

So you'll get even wear. fast or slow.

Anything over 35 I feel like I'm driving round on wooden wheels.
No thank's.

OutbackMK · Senior Member

Yes Woody,
I run a TPMS system and the values are almost spot on against my manual gauge which is a ARB deflater and was tested to be accurate in a number of comparos.
32 front and 35 rear cold. Thats about 35 and 39 hot.
Brian

Cupie · Guru

I dropped my tyre pressure gauge & it read crazy.

So I went & borrowed the neighbour's, then pulled mine apart & adjusted it until it read the same as my neighbour's.

Does that qualify as re-calibrated?

Tony Bev · Guru

Cupie wrote:
I dropped my tyre pressure gauge & it read crazy.
So I went & borrowed the neighbour's, then pulled mine apart & adjusted it until it read the same as my neighbour's.
Does that qualify as re-calibrated?

It is how I use to re-calibrate, pneumatic and hydraulic gauges, on drill rigs out the bush

Just gently bend the bourdon tube, until the bad one, was the same as the good one

Very primitive, but effective, until a new gauge was obtained

Cupie · Guru

Tony Bev wrote:
Cupie wrote:
I dropped my tyre pressure gauge & it read crazy.
So I went & borrowed the neighbour's, then pulled mine apart & adjusted it until it read the same as my neighbour's.
Does that qualify as re-calibrated?
It is how I use to re-calibrate, pneumatic and hydraulic gauges, on drill rigs out the bush
Just gently bend the bourdon tube, until the bad one, was the same as the good one
Very primitive, but effective, until a new gauge was obtained

The term 'Bourdon tube' got me so I used DrGoogle & now I understand what I did. Thanks

http://instrumentationtools.com/bourdon-tube-pressure-gauge-working-principle-animation/

iana · Guru

Tony, how big was the hammer you used?

Tony Bev · Guru

Hello Ian

It is hard to get a hammer close to a Bourdon Tube.

It has to be a finger and thumb job, and very gentle, LOL

Just bending the Bourdon Tube until the needle was just touching the zero stop pin, does not always work.

Putting two gauges together at working pressure, then bending the Bourden Tube to re-calibrate, sometimes meant that at no pressure, the needle (on the damaged gauge), was not on the zero stop

Much better to know that a re-calibrated gauge, was fairly accurate at working pressure, than at the lower pressures

Edit to ask
How close was the tyre inflator, to the master gauge?

-- Edited by Tony Bev on Tuesday 23rd of May 2017 08:44:51 PM

iana · Guru

Tony, my post was initially to see if anyone knew of a way to check the tyre inflator for accuracy. The last thing I need is more work. Making up a rig to test the inflator is just one more job for me, so it will be done down the track a bit. If there were others in Perth that are interested, then I could buy the gauge $39:00, plus fittings, the whole unit cost shared would amount to much. Gosh all you chaps who are retired (I'm just tired) must have sooooo much time to do this stuff!

Tony Bev · Guru

I would be interested to have a link to the $39 gauge, Ian
I assume that we are talking about some sort of master gauge

As you say, some us older chaps, just may have time on our hands, from time to time

smile At my age, I am either bludging, or doing nothing, most of the time smile

iana · Guru

I know you are Perth based, but I wasn't sure if you were somewhere about the country. What we worked out at Pirtek was, If I can get a small cylinder, and I have two I can access, 1/ an old 10kg fire ext., and 2/ a surplus gas 9kg cylinder I have here at home, I will have to have a chat to our friendly Bob-Jane's manager, and get a valve and stem to fit into the cylinder (drill hole). Pirtek would use their fittings and gauge as a master and we would pressurize the cylinder with the tyre gauge/filler and compare the results. If you or anyone else wants to be in on this so be it. It may cheaper o buy the gauge and fittings, but I will have no use for the tester after I have checked my tyre inflator.

iana · Guru

PS I have done gauge testing many, many, moons ago using a hydraulic tester a bit like a set of scales, where you fitted the gauge and then put weights on a platform, gave them a spin, then read the results.

blissonwheels · Senior Member

Gooday,

Sadly been through several types and they all either failed after a while or were far from accurate.

Finally did some Google research and came up with this one which I find very reliable, think it cost me around $100-00 a couple of years ago, have my own great 12 compressor so d o not bother with Fuel Stations unless I do ot have my own gear with me.

Tony Bev · Guru

iana wrote:
I know you are Perth based, but I wasn't sure if you were somewhere about the country. What we worked out at Pirtek was, If I can get a small cylinder, and I have two I can access, 1/ an old 10kg fire ext., and 2/ a surplus gas 9kg cylinder I have here at home, I will have to have a chat to our friendly Bob-Jane's manager, and get a valve and stem to fit into the cylinder (drill hole). Pirtek would use their fittings and gauge as a master and we would pressurize the cylinder with the tyre gauge/filler and compare the results. If you or anyone else wants to be in on this so be it. It may cheaper o buy the gauge and fittings, but I will have no use for the tester after I have checked my tyre inflator.

Hello Ian

I live down South, Perth is only my big smoke, about 200 Kilometres away

I do not think that it is worth the effort to make something, which may or may not be used a second time

I somehow doubt that Pirtex, (they are supposed to be at least, second grade Fit Hairs), would use any old vessel, as an air receiver.

If I was really desperate, and friendly with Pirtex, I would borrow their master gauge.
Place the master gauge on a 240 volt compressor, in place of the original gauge
Let some air out of a spare wheel
Connect the compressor to the spare wheel, and start the compressor
Stop the compressor, when the master gauge is within the range of your working pressure
Leave for a few minutes for the pressures to equalise

We then have a spare wheel at the working pressure, and you can then start checking your tyre gauge/s, at the spare wheel

I have found a master gauge $80 odd dollars plus freight
100 mm face, glycerine filled, 0 - 800 kpa (0 - 116 PSI) accurate to 2.5% (about 0.9 PSI out, at 36 PSI tyre pressure)

I have found an identical gauge, but with a smaller 67 mm face for $34 plus freight

I can not find a master gauge to within 0.5% accuracy, less than a thousand dollars

I have come across a KIncrome, Part No. K8065, digital tyre gauge, ( blankstare digital is easier to read for us older chaps )
Kincrome website says that it is accurate to within (if I have read it correctly)1 PSI at 35 PSI tyre pressure, with a range of 0.5 to 95.5 PSI

One of their distributors is Bunnings
$23.94
It is the same part number
The Additional Bunnings info says
Warranty Info - Kincrome Lifetime Guarantee

I shall see if they have one in my home town tomorrow

Tony Bev · Guru

blissonwheels wrote:
Gooday,
Sadly been through several types and they all either failed after a while or were far from accurate.
Finally did some Google research and came up with this one which I find very reliable, think it cost me around $100-00 a couple of years ago, have my own great 12 compressor so d o not bother with Fuel Stations unless I do ot have my own gear with me.

Hello blissonwheels

Thanks for that info

They no longer make that model, but the new model is just as good, as they come with a certificate of calibration

They guarantee that it is better than the European standard (EUR 31986L0217)

Below is a snip from that standard, (I have added the PSI numbers)

EUR 31986L0217 - Copy.GIF

Tony Bev · Guru

iana wrote:
Have just returned from a trip, the ride to the destination was uncomfortable, tire pressures in the ute were as it came out of a service, and checked by a hand held gauge by me, the setting going by the figures on the vehicle door pillar were for medium to high load. On the return trip I used a new tyre inflator to check pressures, and let about 3 psi out all round, bringing the pressures down to not quite unloaded. The difference in ride was quite remarkable.
I know at work, I have within the last 18 months brought a new tyre inflator and a new gauge, the difference in the readings between both these units is 2 psi. In my own tool box I have a cheap gauge (dial) that I used on this occasion to check the utes tyre pressures, but on the return trip, I used an ARB tyre inflator to check. The cheap gauge is going into the bin.
Now my question is, is there anyway to test (or have tested) the tyre inflator for error?

Yes there is, if you can trust what the manufacture says on their gauge, and then compare your gauge with theirs

The digital KINCROME (not inflator) gauge, says on its packet, and on its instruction sheet, that it is within 1 PSI at 35 PSI
It also says 12 month, and not lifetime warranty

I purchased the KINCROME Model No K8065, digital gauge this morning, and this is what I found

Caravan spare wheel

Kincrome 34 PSI
No name old silver digital gauge 34 PSI
No name newer yellow digital gauge 34 PSI
No name old analog inflator 33 PSI (heard a leak)
No name newer analog inflator 33 PSI
Double check with Kincrome 33 PSI

Motorhome front wheel

Kincrome 75.5 PSI
No name old silver digital gauge 75 PSI
No name newer yellow digital gauge 75.5 PSI
No name old analog inflator 74 PSI (heard another and larger leak)
No name newer analog inflator 76 PSI
Double check with Kincrome 73 PSI

The digital gauges seem to be fairly accurate to each other

The anolog inflator gauges, could well be the way that this older chap reads them, as they only have a 60mm face

I have wrote on my analog inflators, 1 PSI, and 3 PSI over, and have left my oldest digital gauge, near my compressor, as a double check

I hope that this info is helpful to someone, in the future

iana · Guru

Tony, the answer was only a couple of threads down, and I rang up our friendly "Bob Jane" tyre people, and they have a master digital gauge that I can have my gauge compared against. Too simple!