Hi.
I'm Ryan
with Michigan Truck
Spring, Truck Spring.com.
In this video
I'm going to talk to you
about brake chambers.
Brake chambers are used on
heavy duty
trucks and trailers
to convert energy from compressed
air into force
used to apply the brakes.
There are two
main types of brake chambers
used: service
chambers and spring brakes.
Service chambers
apply and release the brakes
and serve only one function
where spring breaks
perform double duty,
applying and releasing the brakes
and also providing a parking
and emergency brake
when air pressure is lost.
In this video,
I'll talk to you about each type,
explain how they work
and the components
inside of them.
First,
I'll start out with service
chambers.
The service chambers
only job is to apply the brakes
when air is sent to the chamber
and to return
to a neutral released position
when air is removed.
Service
chambers will be referred
to by types ranging from Type
6 to Type 36.
On the table here
I have a Type 20.
The type number relates
to the area
and square inches
that the air acts on
so this decides
the amount of force
that the service chamber is
capable of.
Chamber types can
be identified
by markings on the chamber.
This has a seat 20L
or
they can be measured
across the clamp area.
And this chamber measures
about 6 and 5/8 inches.
Service
chambers are simple in operation
and only contain three components
inside: the diaphragm,
a push rod and push plate,
and a return spring.
When air is applied
to the chamber,
the diaphragm pushes forward
on the push rod and push plate,
applying the brakes.
When air is released,
the springs in the wheel
end and brake assembly,
as well as the return spring
and the diaphragm,
pull everything back
into a neutral release position.
Besides the type number
there are also standard
stroke and long stroke
variance of service chambers.
A standard
stroke is a two
and a half inch stroke,
and a long stroke
will have three and a half inches
a stroke or more.
They can normally be identified
by markings on the chamber.
This is a Type 9 and on the clamp
it shows a Type 9
and on the chamber
diaphragm it shows a T 9.
The other chamber I have
here is a 20
Type service chamber,
long stroke,
which is identified
by the number
stamped into the chamber, SC 20L.
Next, I'll talk about
spring brakes.
Spring brakes are split
into two sections
that perform different jobs.
The front section
acts as a service chamber,
it has the same
internal components:
the diaphragm,
push plate,
push rod and return spring.
But the rear section houses
a very powerful
spring that acts
as a parking brake
or an emergency brake
when air pressure is removed.
The rear section
is non serviceable
and you should never attempt
to open it.
The spring inside
this rear section has upwards
of 2,000 pounds of force.
You can easily injure
or kill you.
Any time you perform service
on a spring brake
use a caging bolt
or a T-bolt
to restrain the power spring to
make it safe for service.
This is
a cutaway spring break
that has the power
spring disabled
so you can safely see
the internal components.
There's a piston assembly,
which is the link
between the parking side
and the service side
with a center sealing O-ring
keeping the air pressure
separate between
the two chambers.
The power spring pushes
the piston assembly forward,
forcing the service side to apply
when air is released
from this back chamber.
The air will be released
either by using the parking
brake in the truck
or by an unexpected
release of air
when it acts
as the emergency brake.
There is a diaphragm
that pushes the spring
into a release position
when air is applied
and there is a return spring
that ensures
everything returns
to a neutral position
when the brakes are released
to ensure that there's
no interference
between the service
side and the parking side.
It's important to
pay attention
to the type of spring brake
you have when replacing them.
They come in
long stroke and standard
stroke variants,
which are pretty easily
identified.
The standard stroke
have round bosses
for the air inlets.
With a long stroke
will have square.
Long stroke chambers
will also have
a larger center body
with markings
that will identify them
as a long stroke,
and most of them
will come with a tag
that are identified
as it is a long stroke chamber.
They also come in
different type chambers
or these are both of 30-30.
These have a 30 type
spring brake and a 30 type
service brake.
This chamber is a 24-30.
This has a 24 type
service chamber
and a 30 type spring brake.
You can see that the body changes
diameter as it moves up to the
service brake portion.
Even though the parking
brake is not serviceable,
the entire assembly
can be replaced
with a piggyback assembly
while leaving the service
chamber portion alone.
Just simply cage
the spring break
with a caging bolt.
Remove your airlines
and your front clamp ring.
Install a piggyback
assembly with a new clamp ring.
Attach your airlines.
Remove this caging bolt,
and you're as good as new.
Hopefully this video
has clarified the inner
workings of brake chambers.
If you still have questions
or need help
identifying replacement
parts or brake chambers,
give us a call
at 1-800-358-4751, or,
reach out to us
at Truck Spring.com.