BENDIX SD-02-4500 User Manual
2
FIGURE 2 - PIGGYBACK SPRING BRAKE DIAGRAM
EMERGENCY
PORT
PORT
SERVICE
PORT
MOUNTING
NUT
NUT
COTTER PIN
YOKE
LOCKNUT
SERVICE
PUSH ROD
2. Check push rod to slack adjuster alignment from release
to full stroke position to be sure the push rod moves out
and returns properly without binding at the non-pressure
plate hole or with other structures. Also check the angle
formed by the slack adjuster arm and push rod. It should
be greater than 90 degrees when the chamber is in the
released position and approach 90 degrees at maximum
readjustment stroke.
and returns properly without binding at the non-pressure
plate hole or with other structures. Also check the angle
formed by the slack adjuster arm and push rod. It should
be greater than 90 degrees when the chamber is in the
released position and approach 90 degrees at maximum
readjustment stroke.
3. Check tightness of mounting nuts. Torque on the non-
pressure plate mounting nuts should be 110 ft/lbs.
4. Check cotter pins to ensure they are in place.
5. Check all hoses and lines. They should be secure and
in good condition with sufficient length to allow for axle
movement.
movement.
Every 3,600 operating hours, 100,000 miles or one (1) year:
1. Disassemble and clean all parts. Clean all metal parts
in cleaning solvent, removing all rust and scale. Carefully
inspect all metal parts for cracks, distortion or damage.
All diaphragm sealing surfaces should be smooth and
clean.
inspect all metal parts for cracks, distortion or damage.
All diaphragm sealing surfaces should be smooth and
clean.
2. Install new diaphragm or any other parts if they are worn
or deteriorated. Perform steps outlined in "Replacing the
Service Diaphragm". When the diaphragm, spring, or
both are replaced, they should be replaced in the
corresponding chamber on the same axle.
Service Diaphragm". When the diaphragm, spring, or
both are replaced, they should be replaced in the
corresponding chamber on the same axle.
WARNING!
A piggyback spring brake chamber cannot have the
emergency diaphragm replaced. Replace the whole
piggyback spring brake chamber.
emergency diaphragm replaced. Replace the whole
piggyback spring brake chamber.
OPERATION & LEAKAGE TESTS
OPERATING TEST
1. Apply brakes and observe that the push rods move out
promptly and without binding.
2. Release brakes and observe that the push rods return to
the released position promptly and without binding.
3. Check push rod travel. Push rod travel should be as
short as possible without brakes dragging. Adjust travel
of push rod at slack adjuster if necessary.
of push rod at slack adjuster if necessary.
LEAKAGE TEST
1. Make and hold a full brake application.
2. Using soap solution, coat clamping ring(s). If leakage is
detected, tighten clamping ring only enough to stop
leakage. DO NOT OVERTIGHTEN as this can distort
the sealing surface or clamping ring. Coat area around
push rod hole (loosen boot if necessary). No leakage is
permitted. If leakage is detected, the diaphragm must
be replaced.
leakage. DO NOT OVERTIGHTEN as this can distort
the sealing surface or clamping ring. Coat area around
push rod hole (loosen boot if necessary). No leakage is
permitted. If leakage is detected, the diaphragm must
be replaced.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO
THESE INSTRUCTIONS TO
AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
general precautions should be observed at all times.
1.
Park the vehicle on a level surface, apply the park-
ing brakes, and always block the wheels. Always
wear safety glasses.
ing brakes, and always block the wheels. Always
wear safety glasses.
2.
Stop the engine and remove ignition key when
working under or around the vehicle. When work-
ing in the engine compartment, the engine should
be shut off and the ignition key should be removed.
Where circumstances require that the engine be
in operation, EXTREME CAUTION should be used
to prevent personal injury resulting from contact
with moving, rotating, leaking, heated or electri-
cally charged components.
working under or around the vehicle. When work-
ing in the engine compartment, the engine should
be shut off and the ignition key should be removed.
Where circumstances require that the engine be
in operation, EXTREME CAUTION should be used
to prevent personal injury resulting from contact
with moving, rotating, leaking, heated or electri-
cally charged components.
3.
Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended proce-
dures. Use only the proper tools and observe all
precautions pertaining to use of those tools.
assemble a component until you have read and
thoroughly understand the recommended proce-
dures. Use only the proper tools and observe all
precautions pertaining to use of those tools.
4.
If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air sys-
tems, make certain to drain the air pressure from
all reservoirs before beginning ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
brake system, or any auxiliary pressurized air sys-
tems, make certain to drain the air pressure from
all reservoirs before beginning ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
™
air dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.
sure to drain the purge reservoir.