Tyre Pressure Gauge Calibration - Nigel Hodgson
Is there an easy way of calibrating tyre pressure gauges?

When my Focus went in for a service at a Ford Dealer all my tyre pressures were upped by 4 psi during the service (I checked them before and after). Do they calibrate their gauges? If so then I can calibrate mine against theirs.

I somehow doubt they do. They should.... Maybe I should ask!

Is it possible to buy a gauge which is certified as calibrated? I bought one from Snap On, but there was piece of paper so say that the calibration was checked.

Nigel Hodgson
Re: Tyre Pressure Gauge Calibration - David Lacey
As a condition of our Manufacturer Franchise Standards, all tyre pressure guages, torque wrenches and belt tension guages are calibrated and certified at six-monthly intervals. These certificates are readily available for inspection - they are actually displayed in our Service Reception
I have lost count of the number of comments from customers stating that the tyre pressures after a service have been found to be incorrect. I refer them to our certificates and explain the general inaccuracies in forecourt/DIY tyre pressure equipment
As a note of interest, the Snap-on guage you have could well have been calibrated to a different standard (Being of a foreign origin) but this should make little difference in the end results
I suggest you ask the dealer if their equipment is calibrated, tell them of your concerns - and ask to see any certificates - I would readily make these available
Re: Tyre Pressure Gauge Calibration - Nigel Hodgson
Many thanks for this - I didn't presume my gauge was correct, in fact I would have been suprised if it was. However I now have a rough calibration on my gauge.

I'll take this up with my dealer. I also note HJ has a FAQ topic on gauges.
Torque wrench calibration. - David Woollard
Re. David Lacey's spot on comments.

If one more person mentions them I will get started on cheap torque wrenches!

David
Re: Torque wrench calibration. - David Lacey
Hmm, interesting question Alyn. Depending upon make, take it to the nearest authorised dealer. Britool have their own calibration dept, Snap-on have theirs and I'm sure all the other manufacturers worth their salt have them too. Try their websites.
The people who calibrate our equipment - Autocal - are very helpful & efficient - try looking on the web for them.
As a last resort, find a local main dealer and ask if your torque wrench can be included when theirs are done. It shouldn't be a problem in my eyes and shouldn't cost more than £15ish
Good luck
David
Success for the dealer. - David Woollard
Nigel,

Nice to hear the dealer has set all 4 pressures to a consistant figure, but what about the spare?

I took on a three year old main dealer serviced XR2i the other year. First check the thirtysomething female owner wanted was on all the tyres prior to a Lake District holiday.

The valve for the underbody mounted spare wasn't visible without dropping it down, and that took a while as it was seized from never being moved. Original new spare tyre, remaining pressure 7psi!

Lucky she didn't find out all that on the side of a wet dark motorway. Very very lazy of them.

But back to your guys and the correct pressure. If you have a SnapOn gauge that will be a decent one. If it was one of the unbranded £3.99 models from the market I wouldn't trust it. The dealer is likely to have a much more accurate gauge than that, just ask him and then check yours against it.

I usually inflate a couple of pounds over the "driver only" setting, a few people comment I seem to have set the tyres 4 - 5psi too high. But I know my gauge is right and anyway that is erring on the safe side.

And don't even get me going on cheap DIY torque wrenches.

David
Re: tyre presures. - andrew smith
My car lists the recommended tyre pressures between 32 psi for 1 brick and 42 psi for 3 bricks (fully laden I guess). I've gone for 35 as a good inbetween figure but the manufacturers recomendadtion leaves so much room either side of this that just about anything would be OK. The upshot of this is that even a inaccurate gauge will allow you to get all 4 tyres within this range. More important might be to get all 4 tyres the same.
I am, however, careful to set the pressures with the tyres cold to avoid underinflation.
Re: Torque wrench calibration. - Brian
Better than cheap talk wenches !
Re: Torque wrench calibration. - David Woollard
Brian,

Bet I get more than five words on the BX!

David
Re: Torque wrench calibration. - Brian
David,

You've lost your bet

Brian
Re: Torque wrench calibration. - Alyn Beattie
How can aprivate individual (like me) get a torque wrench calibrated?
Re: Torque wrench calibration. - Don Cox
Alyn
It depends whether or not you are impressed by bits of paper that say the calibration has been checked. If on the other hand you want to check it for yourself, all you need is to clamp the square drive in a vice so that the wrench lies horizontally, set it to the minimum setting, hang a suitable known weight at a distance measured from the centre of the square drive which will achieve the torque indicated and watch the result. Repeat the exercise for the largest setting. any variation in the settings you have to make to make it click, collapse or read off correctly on a scale obviously indicates inaccuracy. For practical purposes a decent spring balance pulled at right angles to the shaft can replace the weight and a Newton can be taken as a 100 grams
( 0.1 Kg ). Torque = Force (weight in this case) X Distance
What you do about it if it's wrong depends on the make, Britool ones can be adjusted by altering the number of washers on the end of the spring locater, the rest I don't know much about.
Regards
Don Cox
Re: Torque wrench calibration. - Pete Mansell
I usually check my torque wrench myself, using a spring balance. If you apply, say 30 pounds to your wrench via the spring balance, and the wrench is say, one foot long, that is 30 pound feet. A simple calculation will work for any length wrench. If you are worried about the calibration of the spring balance, simply check with a known weight. (1 gallon of water weighs 10lb!)
Re: Torque wrench calibration. - Alyn Beattie
thanks all for your answers
Re: Torque wrench calibration. - graeme clark
Pete.

That is an imperial gallon..a us gallon is 8lbs..

Now i am not one to split hairs,,,but...

Graeme
Re: Torque wrench calibration. - Andrew Hamilton
I had a total of 5 tyre pressure gauges collected from my relatives and took them to trading standards some years ago. They tested them all for free over a variety of pressures and I got a printed summary. Great service.
It was interesting that the maximum error was about 1psi and did not depend on age.
Re: Torque wrench calibration. - Brian
Or if it's a metric gauge, 1 litre of water = 1 kilogram
 

Value my car