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[HOW TO INSPECT TIRES TO PASS YOUR CDL PRE-TRIP INSPECTION TEST] [BANGING TIRES WITH A HAMMER] Hi there, Rick with Smart Drive Test talking to you today about tires on commercial vehicles, not just trucks, but this applies to buses as
well. In a pre-trip inspection we whack the tires. Now there is some discrepancy
on this point. My firm belief is is that the only thing that whacking a tire is going to
tell you, is whether this inside dual is flat or not. Because it’s being held up
by the tires on the outside. Some driving instructors and some other people— truck
drivers and what not—believe that they can tell the difference of a few pounds
of pressure in these tires. I’m not on board with that at all. These tires hold
a hundred pounds of pressure; that’s what the recommended inflation pressure is.
There is some belief in the industry that if they’re 10 percent less— so ninety
pounds of air—they’re under-inflated. Today we’re gonna talk about tires on
commercial vehicles and give you some information so that you can stay
employed for one thing, and keep your job, keep rolling up and down the road. We’ll
be right back with that. [OPENING CREDITS & MUSIC] Hi there, Rick, welcome back. Talking today about tires on big trucks. On the rear of vehicles, these four tires the tandems, & the tires on the rear of
the trailer – back there can be retreads. So what they do is they take the old
casing when when the tread wears off, and they take it to a Kal Tire, or
one of the other big tire manufacturers— Michelin, Goodyear— all those places and
they put a new tread on top of the casing. So this is important for drivers
to know because if your’re driving around and you get a flat tire you don’t want
to run around until the casing is wrecked. Because that casing alone is worth
about $175. So it’s important to know not to wreck the casing. Now the other thing
you need to know about tires on the back of the truck: these are 22.5s – a lot of
tires are 24s – those are the two most common sizes so obviously the 24 is
bigger. And why this is important is because: A) there is a little bit of fuel
mileage benefit because the tire doesn’t roll as much on a bigger tire. B) also when you
dropped trailers—semi-trailers—off the back of a big truck, it drops the
trailer at a different height so it’s important when you’re hooking up to get
out and check the trailer height. Because if the trailer is too high, you’re gonna drop the kingpin over the front of
the fifth wheel. And let me tell you from personal experience it’s a bit of a pain in
the butt to get that out of there. And I’ll make another video to explain to you—if
you do drop the kingpin over the front of the fifth wheel—how to get that out
of there. So tires on the back of trucks and semi-trailers are retreads. A lot of
people in the industry they’re called Gators. If you get a hunk of retread that
comes off and flies on the road, it’s called a gator because it takes a bite of your
vehicle if you run over it. It’s becoming less and less common that the retreads are flying off these tires. I
mean it still happens once in awhile but the adhesive— the vulcanizing process—that they use to adhere the retread to the casing is getting better and better. The
chemical technology and improvements are getting much better.
So these retreads come apart on a lot less frequent basis. This is the front steer tire on a truck.
Front steer tires have to be brand new. They cannot be retreads as they can on
the back of the truck and on the semi-trailer – they have to be brand new.
Now you need to know for the purposes of a road test that tread depth on the
front is 3mm (1/8 inch) minimum to pass the road test or to pass and MVI (Motor Vehcile Inspection) that the tread depths. On the rear tires it can be 1/16 inch or 1.6mm. The other criteria that a tire has to
have to pass a road test – it cannot have any cuts are gashes in the tire
that are longer than 2.5cm or one inch, and there cannot
be cuts or abrasions in the tire that expose the chord inside the tires. If any of
those criteria exist, the tire won’t pass, will not pass an MVI; you will not pass
a road test, and if you show up with tires with those conditions for road
test, you won’t be able to take the road test.
On the top of this tire—this is a front tire—on this truck you begin to see that
this tire is beginning—there’s a dip here in the tread. This tread is worn deeper than this tread. And this side – so this tire has uneven wear – you can see that it’s
worn more on this side of the tire than it is on this side of the tire. This
front tire on this truck is not safe and needs to be replaced. Tires on the front of
commercial vehicles have to be brand new. After you pass your road test, you don’t
really need to know the information that is required in terms of 1.6mm on the rear, 3mm on the front, and gashes that
are not longer than 2.5cm. What you do need to know is inside the
tread are wear bars. And you can see the wear bars here. If the tire tread is down
to wear bars on the steer tires on the front, the tire needs to be replaced. Now
as I said, steer tires on the front of the trucks—commercial vehicles, buses those
types of things—have to be new tires. A new steer tire on the front of a commercial
vehicle is$600 to a $1000, depending on the type of tire.
This tire is not a very expensive tire, thus it’s abnormally worn on the front and will
soon need to be replaced. So you either spend a little bit more and get a better quality
tire and it’ll last longer. Now the reason, because a front steer tire is $600—$1,000 – the reason they put recaps on the rears and on the trailers is because
a recap will cost you about $375—$400. There’s considerable saving in getting
recaps for the rear of semi trucks and the trailers. They’re also allowed on the rear of
buses, but not on the steer axles. They have to be brand new. That’s a little bit of information about tires on commercial vehicles. In conclusion, tires on commercial vehicles – on the front they’re brand new tires. They have wear bars on them. You can tell that
the tires worn because it’ll be down to wear bars on the steer tires. On the rear
of the truck or bus or semi-trailer, they can be recaps. A recap is about $375; a
brand-new steer tire is $600—$1,000 depending on the quality of the tire. Recaps are
about $375—$450 – considerable savings on recaps. The vulcanizing process to put
the tread on the old casing is getting much better, so it’s unlikely that you’re
gonna see Gators on the road – pieces a retread. They take a bite out of
your vehicle & they’re called Gators. Hitting a tire with a hammer, in my
professional opinion, only tells you the inside of the tire is flat. The only way
that you’re gonna be able to tell if that tire is full pressure—hundred pounds per
square inch—is if you put a tire gauge on the tire and have it pumped up.
Now just on that note, if the tire is low pressure and you see this on trailers a
lot. They get dragged around and they got low tire pressure – you’ll see a wave in the
chords because the chords let go inside the tire and it’s an indicator that the
tire needs to be replaced because it’s no longer safe and no longer will pass
a MVI. If you get pulled into a scale they’re probably gonna put you out of service
because the tire isn’t up to standard. For the purposes of a road test: one point six
millimeters on the rear tires; three millimeters on the front; any gouges longer than 2.5 centimeters.
And any cuts or abrasions in the top of the tires that expose the chords. I’m
Rick with Smart Drive Test, thanks for watching. If you like the channel, subscribe below; Hit that like button. And pop over to the
website, sign up, get your free weigh scale checklist. If you get pulled into a scale
and you’re a new driver, you’re going to need a checklist of paperwork that you need to
bring into the scale house. It can be somewhat extensive. The checklist will help you
out so your visit to the scale is nothing but a minor inconvenience going
down the road. Get that, it’s free at my website. Thanks
very much for watching. I’m Rick with Smart Drive Test. All the best going up and
down the road. Remember, pick the best answer, not
necessarily the right answer. Have a great day! Bye now. [CLOSING CREDITS & MUSIC]

5 thoughts on “How to Inspect Tires to Pass Your CDL Pre-trip Inspection TEST

  1. You never ever want to hit those tires with anything I’ve seen people do that and have the tire explode on them the tire pressure can be anywhere between 95 and 120 psi and remember when a tire explodes it can lift the truck off the ground always use a tire gauge

  2. Make sure you match tire casing brands side by side. Different brands flex at different areas and at different rates on the sidewall and can cause uneven wear called cupping. The only brands that match are Firestone and Bridgestone.
    Also ensure your side by side treads are the same as well as tread depths. Tread depths can vary 9/32 or less.
    This is not a road rule that causes and out of service but is recommended for safety and truck wear and tear. Tread depth difference even cause the diffs to heat up. If you notice 5 to 10 degree difference in your differentials then normal then look at your tread depths.

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