Then after the release bolt has been backed off, the air
pressure must be released from the parking brake
system by placing the brake control in "apply" position.
In this manner, you will have the air pressure in the
system to assist in caging the spring.
Do not apply more than 68 N.m (50 ft lbs) torque to
If the release bolt should bind, apply "Liquid Wrench"
or equivalent to the bolt and allow to soak into the
In the event the air source has been depleted, the
release bolt may be backed off in the same manner;
however, turning the release bolt will require more effort
since the parking brake spring will be fully extended, and
when turning the bolt you will actually be pulling or
collapsing the spring manually.
MANUAL SET OF SPRING BRAKE
If the release bolt threads are dry apply a light coat of
"Never Seez" lubricant or equivalent to the threads. Do
not apply "Never Seez" lubricant supplied in an aerosol
To manually reset parking brake at each spring brake
chamber, screw release bolt down into unit until nut is
bottomed against the head insert. Torque nut to 61-68
N.m (45-50 ft lbs) and reinstall breather caps with arrow
pointing toward ground.
The breather cap must be in place and the arrow on the
breather cap must point down. The breather cap should
be checked periodically. If dirty or clogged, a new
breather cap should be installed. When the breather cap
is removed, check the release bolt nut to assure it is
tightened (clockwise) to 68 N.m (50 ft lbs) torque.
The spring brake and service brake chamber clamp
rings should be checked periodically to insure the clamp
is evenly sealed and clamp bolt nuts are tightened to 27-
34 N.m (20-25 ft lbs) torque.
To avoid personal injury never remove the
spring brake clamp ring unless manual
release mechanism has been applied as
SPRING BRAKE and assembly is placed in
a caging fixture.
Visually inspect exterior surfaces of assembly for
Be sure to check mounting stud nuts are tightened to
136-156 N.m (100-115 ft lbs).
Air line fitting should be checked to be sure they are
torqued to 34 N.m (25 ft lbs).
Check service brake chamber pushrod to insure it has
free motion and is in straight alignment from service
chamber to slack adjuster. Worn yoke pins are to be
replaced and are locked in place with a cotter pin. Make
sure the jam nut is tight.
Some parts, such as air brake chamber
diaphragm, should be inspected once a
year or every 80,000 km (50,000 miles)
and replaced if considered unserviceable
for further use.
Regular lubrication of the double diaphragm spring brake
chamber is not required; however, when the unit is
disassembled, all parts must be washed in clean solvent
and IH 251H EP grease or equivalent NLGI #2
multipurpose lithium grease applied to release bolt,
pushrod, seals and white plastic guides, outside of
diameter edge of spring piston and guide surface of
If the threads on the release bolts are dry a light coat of
"Never Seez" lubricant should be applied to the threads.
Do not use "Never Seez" lubricant supplied in an aerosol
Block the wheels of the vehicle to prevent it from
Manually release the spring brakes (refer to
MANUAL RELEASE OF SPRING BRAKE).
After releasing brakes release the air pressure in
she parking brake system by placing the
parking brake control in apply" position. Be
sure that the service brakes are released also.
Remove air hoses fron parking brake and
service brake chambers. Tag hoses for
proper identification at reassembly.
Loosen jam nut at service brake pushrod yoke.
Disconnect service brake pushrod yoke from
CTS-4101W - Page 5