[TITLE & MUSIC]
Hi there smart drivers, Rick with Smart Drive
Test talking to you today about how to
adjust a manual slack adjusters for the
purposes of your CDL license test. You
are not going to do this on any modern
air brake system. They're all going to be
equipped with automatic slack adjusters.
As you can see here in the salvage yard
I had to walk around here for about a
half an hour before I actually found
this old, probably 1970s maybe early 80s
Ford Louisville that that is equipped with
manual slack adjusters. You can tell how old
the truck is because it actually says on
the hood "diesel engine" which signifies
the transition between gasoline engines
and diesel engines for big trucks that
happened in the early 1970s. And that was
one of the selling features for this old
Ford Louisville. And at one time the Ford
Louisville actually was the industry
standards - it's a pretty old truck. So
you're not going to ever have to adjust
the manual slack adjuster. It's really
unlikely because they've gone the way to
the way of the dodo bird, but for the
purposes of a road test--a CDL license
test--you're going to have to do it. So
we're going to do that today. We're going
to show you how to do it. And at some
licensing centers--here in British
Columbia for example--if you cannot
explain how to set up a manual slack
adjuster it's an automatic fail on the
air brake portion of your CDL test. So
you have to be able to do it. If you go
down with a school, they're going to have
a vehicle that has a manual slack
adjuster on it and you have to
demonstrate it or you have to give a
verbal. The driving examiner will just
show you a picture of a manual slack
adjuster and you'll have to give a
verbal. So the steps are: chock the wheels,
pump the air pressure over a hundred
pounds per square inch (690kPa), release the parking brakes, get
out and determine that it is in fact the brake is out of
adjustment by using the pry bar method
for the most part - you might have to use
the applied stroke method and I'll put a
card up in the corner for you here on
determining air brake adjustment. Once
you determine that it's out of
adjustment you take your 9/16" wrench,
push it over the adjusting nut - you'll
have to release the locking sleeve and
we'll show you how to do that. And then
turn the adjusting nut so the S cam
rotates in the same direction as a brake
application we'll show you that's key I
turn the adjusting nut so the S camera
rotates in the same direction as a brake
application then you turn it all the way
until the nut goes tight and you
shouldn't have to turn it more than one
or two revolutions at the most if you're
turning it more than one or two
revolutions you're probably going the
wrong
wait turn until it goes tight check that
it is in fact tight because what you've
done is manually tightened are manually
applied the break manually apply the
break take your wrench and back it off a
third to half a turn and then make sure
the locking sleeve is reengaged
over the adjusting nut the nine
sixteenths nut put your bribe bar in and
make sure that it's within adjustment
after you do that you have to adjust
both manual slack adjusters on both
sides of the axles so know that as well
that if you do one you've got to do the
one on the other side of the axle as
well so what we're going to do today
we're going to demonstrate how to do
that so stick around we'll be right back
with that information x mark drivers
welcome back Rick with smart drive test
talking to you today about how to adjust
a manual slack adjuster for the purposes
of a CDL license test as I said in the
introduction it's not likely in this day
and age on an air brake system you're
going to find manual slacks it's really
unlikely now to get started you're going
to need a 9/16 inch box end wrench
you're going to need a set of wheel
chocks to secure the vehicle against
movement you need a pry bar if you're
doing the pry bar method if you're doing
the applied stroke method you're going
to need a measuring device and something
to mark the push rod at a fixed position
so you can measure how far comes out of
brake chamber as well you're going to
need a pair of gloves
always wear a pair of gloves when you're
working on the vehicle that way you can
keep the dirt outside of the vehicle
when you get into the vehicle you can
take your gloves off but as again as I
said this is only an exercise for doing
a license test and those are the tools
that you're going to need now minimum
you're going to need a hammer a 9/16
inch wrench and a pair of gloves and
that'll get you going on being able to
adjust a manual slack user now for the
most part on most license tests you're
just going to have to do a verbal and
the two key phrases that you say are I
turn the adjusting nut in the same
direction as the S cam rotates for a
brake application and we'll show you how
to determine that as well we're going to
show you that how to re-engage the
locking sleeve over the nut that's the
last piece that you have to say so those
are the two key phrases and again I'll
leave a description down in the
description box here
or complete written list checklist of
things that you need to do to adjust the
manual slack adjuster and find that down
in the description box first thing we
have to do is we have to push in the
locking sleeve on the 9/16 box and we
need the adjusting nut so this is the
adjusting on here you push that in you
can see this one goes in fairly easy now
you might need a hammer and bang on the
box and to get that in so the first
thing we need to do for adjusting a
manual slack adjuster is we put the pry
bar on here and we can see that it's a
little bit loose here actually I'll just
adjusted just it off here a little bit
man you can see that it's actually out
of adjustment so we put our pry bar in
here and we can say okay that's out of
adjustment so the first thing we need to
do is you need to put our wrench on here
push the locking sleeve in and then we
turn it so that the S cam rotates in the
same direction as a brake application so
the way that we determine that is the
push rod extends this way out of the
brake chamber and we think of it like a
wrench on a nut so this is coming out so
we turn it this way so the S cam has to
rotate in this direction when we're
turning the adjusting nut so this is the
only piece when we turn this adjusting
nut here this s cam the end of the S cam
right here is the only thing that should
rotate so we put our 9/16 wrench on the
adjusting nut we turn that we can see
that the S cam is rotating in this
direction the same as the wrench on the
nut this way here so we put that on
there and we turn the adjusting nut
until it goes snug so it's snug so we
take it off we get our pry bar and put
it in the STR in the at the clevis pin
here we try and pry the push rod out of
the break chamber and it doesn't come
out so that means that we've manually
adjusted the break so now we put the
wrench back on at 90 degrees in this way
and we want to go back a quarter to a
half a turn so we come back just a
little past a quarter turn we make sure
that the locking sleeve comes out and it
has in fact we put our pry bar back on
and we make sure 1/2 to 3/4 so we can
see that it is now in fact adjusted so
this locking sleeve does not fully
encase the adjusting nut on here most of
them do but this one doesn't for
whatever reason so we can just try and
move that a little bit and sometimes you
can tap the end of the bolt too and that
will bring me adjust the locking sleeve
out over the adjusting nut but this has
to be in fully engaged over the
adjusting nut and that's the last thing
that you say to the examiner is I would
ensure that the locking sleeve is
engaged over the adjusting nut because
if it's not engaged it's just going to
go out of adjustment again so after you
finish adjusting this one you go over
the other side so again quickly pry bar
make sure it's out of adjustment this
way here we figure out which way that
the S cam rotates for a break
application think of it like a wrench on
a nut so the push rod extends this way
therefore it's going to rotate in this
direction in a counterclockwise
direction so we put our 9/16 wrench on
the adjusting nut and we turn that until
it goes tight and we can see that this s
cam is rotating in a forward motion
towards the front of the vehicle which
is the correct way the adjusting nut has
gone tight we check to make sure that
the push rod will not extend out of the
break chamber because we've manually
applied the brake which it has and now
we take the adjusting nut and we crank
it back a quarter to a half a turn so we
just go past a quarter of a turn there
we make sure that the locking sleeve is
re-engaged and we make sure that the
push rod is within adjustment and it is
within adjustment which is the width of
our thumbnail and that's how you adjust
a manual slack adjuster a quick review
of manual slack adjuster as I said for
the purposes of a CDL license test
you're going to have to do this before
actually adjusting up a manual slack on
a modern air brake system it is very
very unlikely that you're going to have
to do this as I said Coldstream truck
parts here in Vernon I walked around
this yard here for a good half an hour
before I found this old Ford Louisville
that
they had manual slacks on the front of
it that I could demonstrate to you how
to adjust up a manual slack and know as
well here in British Columbia and some
other jurisdictions if you cannot
explain or demonstrate how to do how to
adjust the manual slack adjuster that's
an automatic fail on your air brakes so
just know that as well and you and in
some cases you're going to have to get a
give a verbal especially if you don't
have a vehicle that doesn't have manual
slacks on it if you're going with a
training truck there's a good chance
it's going to have manual slacks on it
that you can demonstrate that but for
most part you're going to need to do a
verbal so the tools you need when you're
doing the primary methods you're going
to need a pry bar you're going to need a
pair of gloves you can either a hammer
and you're going to need a 9/16 inch box
and wrench all manual slack adjusters
have an adjusting nut that is a 9/16
adjusting nut so you're going to need a
9/16 box and wrench to adjust up the
manual slack duster so the first thing
you do
chalk the wheels and ensure that you
have system pressure over a hundred
pounds and release the parking brakes on
the unit then you come out you determine
that it is in fact out of adjustment you
determine which way the S cam has to
rotate to make a brake application think
of it like a wrench on a nut so you just
whichever way the push rod extends out
of the brake chamber just follow that
around and that's the direction that the
you're going to turn the adjusting nut
so the S cam rotates in the direction of
a brake application as you saw here when
we did this one here so you release the
locking sleep over the nut turn the
adjusting nut so the S cam rotates in
the same direction as a brake
application turn it until it goes tight
if you turn it more than one or two full
revolutions you're probably going the
wrong way so once it goes numb then you
take your pry bar pry on the push rod
you should not extend out of the brake
chamber because you manually applied the
brake and then at that point you take
the adjusting nut and you back it off a
quarter to a half a turn usually just
about a third is really good that's
generally the best so you back it off
make sure the locking sleeve re-engages
and then take your pry bar and make sure
that it's within adjustment and if
you're doing the pry bar method it
shouldn't come out of the brake chamber
more than the width of your thumbnail
and then finally if you do one on one
side of the axle you'll have to go over
and do the other one on the other side
of the axle so that's how you adjust a
manual slack adjuster for the purposes
of a CDL license
test question for my smart drivers after
you got your CDL license have you
adjusted up a manual slack adjuster
leave a comment down in the comment
section there all of that helps out the
new drivers working towards getting
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that thumbs up button check out all the
videos here on the channel if you're
working towards the license or starting
a career as a truck or bus driver lots
of great information here as well head
over website awesome information over my
website and tremendous online courses
that you can purchase as well the air
brake course is available over there
that you can purchase and take and in
May 2017 we're bringing out air brakes
explained simply it updates the 40 year
old air brake manuals in North America
that are currently in circulation as
well it has a hundred multiple-choice
questions that you will find on a CDL
license exam so look for that in May
2017 I'm Rick with smart drive test
thanks very much for watching good luck
on your road tests and remember pick the
best answer not necessarily the right
answer have a great day bye now
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