BENDIX TW-2 User manual

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Figure 1 – Bendix®TW-2™, TH-3™and PE-4™Control Valves Maintenance Kit
BENDIX®TW-2™, TH-3™AND PE-4™CONTROL VALVES MAINTENANCE KIT
Position
1
Position
2
Position
3
Screw
Lever/Cam
Pin
Plunger
(x2)
6
54
3
2
Inlet Plate
Lock Washer
Cap Screws
Body
Spring
Lever Positioner
Figure 1
Figure 2
Figure 3
*NOTE: Some valves (TW-2, TH-3
and PE-4) use a single large inlet
plate o-ring and some models use
two smaller o-rings.
Kit Contents
Item No. Description Qty.
2* Inlet Plate O-Ring 1
2* Inlet Plate O-Ring 2
3 Valve Spring 2
4 Valve 2
5 Plunger Spring 2
6 Plunger O-Ring 2
7 Tube of Lubricant 1
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GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS
TO AVOID PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:
▲Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
Always wear personal protection equipment.
▲Stop the engine and remove the ignition key
when working under or around the vehicle.
When working 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 electrically-charged
components.
▲Do not attempt to install, remove, disassemble
or assemble a component until you have read,
and thoroughly understand, the recommended
procedures. Use only the proper tools and
observe all precautions pertaining to use of those
tools.
▲If the work is being performed on the vehicle’s
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with a
Bendix®AD-IS®air dryer system, a Bendix®DRM™
dryer reservoir module, or a Bendix® AD-9si®air
dryer, be sure to drain the purge reservoir.
▲Following the vehicle manufacturer’s
recommended procedures, deactivate the
electrical system in a manner that safely removes
all electrical power from the vehicle.
▲Never exceed manufacturer’s recommended
pressures.
▲Never connect or disconnect a hose or line
containing pressure; it may whip and/or cause
hazardous airborne dust and dirt particles. Wear
eye protection. Slowly open connections with
care, and verify that no pressure is present. Never
remove a component or plug unless you are
certain all system pressure has been depleted.
▲Use only genuine Bendix®brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, fi ttings, wiring, etc. must
be of equivalent size, type and strength as original
equipment and be designed specifi cally for such
applications and systems.
▲Components with stripped threads or damaged
parts should be replaced rather than repaired.
Do not attempt repairs requiring machining or
welding unless specifi cally stated and approved
by the vehicle and component manufacturer.
▲Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
▲For vehicles with Automatic Traction Control
(ATC), the ATC function must be disabled (ATC
indicator lamp should be ON) prior to performing
any vehicle maintenance where one or more
wheels on a drive axle are lifted off the ground
and moving.
▲The power MUST be temporarily disconnected
from the radar sensor whenever any tests USING
A DYNAMOMETER are conducted on a vehicle
equipped with a Bendix® Wingman®system.
▲You should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the Guidelines above.
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REMOVAL
1. With the vehicle on a level surface, park the vehicle
by means other than the air brakes and drain all air
pressure from all reservoirs.
2. Identify all air lines and their connections to the valve
and disconnect.
3. Remove the two Phillips®head screws securing the dial
plate to the valve and dash panel and remove the valve.
DISASSEMBLY
NOTE: Before beginning disassembly of the valve, mark
the relationship of the lever and cam to the body. The lever
must be placed back in the valve body in the same position
in order to ensure proper operation. DO NOT change the
lever position end for end. Most lever/cams have a locating
slot cut in them.
1. Remove the cap screws and lock washer and remove
the inlet plate. Note whether one or two inlet plate
o-rings (2) are used. *See note on page 1.
2. Remove and discard the o-ring (2), both springs (3) and
both inlet valves (4).
3. Remove the pin and lift the lever out of the body.
4. Remove both plungers and their return springs (5).
5. Remove the lever positioner and its spring, if the valve
is so equipped.
6. Remove the o-ring (6) from both plungers and discard
the o-rings.
ASSEMBLY
Prior to assembly, clean the lever and valve body in
mineral spirits and dry thoroughly. Lubricate o-rings and
o-ring bores with the lubricant (7) supplied with this kit.
1. Install both inlet valves (4) and inlet valve springs (3) in
the valve body.
2. Install the o-ring or o-rings (see NOTE* on page 1) in
the valve body.
3. Install the inlet plate and secure with cap screws and
washer. Torque to 50-180 in-lbs.
4. Install the o-ring (6) on the plungers.
5. Install the plunger return springs (5) and install the
plungers in the valve body.
6. Install the lever positioner spring and lever positioner if
valve is so equipped.
7. Note the markings made on the lever/cam and valve
body during disassembly and position the lever in the
valve body.
8. Install the pin to secure the lever/cam.
OPERATING AND LEAKAGE CHECKS
Connect a 100 psi air source to the supply port(s) and
connect an air gauge to each delivery port. With the lever
in the number 1 position, as noted in Figure 3, apply a soap
solution to the exhaust openings in the valve body. No
leakage is permitted. Note which delivery gauge registers
pressure (if either do). Move the lever to position 2, if the
valve has this position, and wait 20 seconds before applying
a soap solution and checking the delivery port gauges.
Repeat this procedure for position 3.
INSTALLATION
1. Remount the valve in the dash panel using the two
Phillips head screws to secure the dial plate and valve.
2. Notingtheairlineidenticationmadeduringremoval,
reconnect the air lines to the proper ports.
3. Before moving the vehicle, build the air system pressure
and operate the valve to determine if it functions
properly in the system. If operation is incorrect, check
the lever/cam installation and the air line connections.

S-0308 Rev. 002 © 2019 Bendix Commercial Vehicle Systems LLC, a member of the Knorr-Bremse Group • 12/19 • All Rights Reserved
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