Maintenance Manual 34
System Saver Series Single Cartridge Air
Dryers
System Saver Series
•1200E, P, U
•1800E, P, U
•1200 Plus, MCP
Revised 03-16
Service Notes
WARNING
CAUTION
About This Manual
This manual contains maintenance procedures for Meritor WABCO’s
System Saver Series single cartridge air dryers.
Before You Begin
1. Read and understand all instructions and procedures before
you begin to service components.
2. Read and observe all Warning and Caution hazard alert
messages in this publication. They provide information that can
help prevent serious personal injury, damage to components,
or both.
3. Follow your company’s maintenance and service, installation,
and diagnostics guidelines.
4. Use special tools when required to help avoid serious personal
injury and damage to components.
Hazard Alert Messages and Torque
Symbols
NOTE: Notes are included to provide the user with supplemental
information, which is helpful but does not necessarily belong in the
core text. Many operational and procedural tasks are easier with the
addition of notes.
How to Obtain Additional Maintenance,
Service and Product Information
Visit Literature on Demand at meritor.com to access and order
additional information.
Contact the Meritor OnTrac™ Customer Call Center at
866-668-7221 (United States and Canada); 001-800-889-1834
(Mexico); or email OnTrac@meritor.com.
If Tools and Supplies are Specified in
This Manual
Contact Meritor’s Commercial Vehicle Aftermarket at
888-725-9355.
Warnings are included to alert the user that possible hazards
are associated with the processes/procedures described.
These may cause death or injury in any form, if the
instructions in the operational or procedural task are not
followed precisely. Warnings describe the potential hazards
and possible impact that could occur if the warnings are not
observed.
Cautions are included to alert the user than damage to the
equipment is possible if the instructions in the operational or
procedural task are not followed precisely. Cautions describe
the hazards and possible impact that could occur if the
cautions are not observed.
@ This symbol alerts you to tighten fasteners to a specified torque
value.
Information contained in this publication was in effect at the time the publication
was approved for printing and is subject to change without notice or liability.
Meritor WABCO reserves the right to revise the information presented or to
discontinue the production of parts described at any time.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Contents
pg. pg.1 Section 1: Introduction
Overview
Other Publications Related to Meritor WABCO System
Saver Series Single Cartridge Air Dryers
Air Dryer Identification
2 How the Air Dryer Works
3 Air Dryer Cycle
7 Air Dryer Components
10 Dryer Identification
Description of Components
14
Section 2: Component Removal and
Installation
Component Replacement
Requirements
15 Component Removal and Installation
Desiccant Cartridge
16 Outlet Check Valve Assembly
Heater Assembly
17 Turbo Cut-Off Valve Assembly
18 System Saver 1200 Plus Governor
Regeneration Valve Assembly
19 Purge Valve Assembly
20 Pressure-Controlled Check Valve (PCCV)
21 Bypass Valve
22 Pressure Relief Valve
Purge Silencer (Muffler)
23 Air Dryer Assembly
35
Section 5: Appendix II — Application Info
Requirements
Operating Environment
36 System Saver Series Installation Criteria
37
Section 6: Appendix III — Special
Applications
Description
Holset E-Type Compressor Systems
38 ECON Valve
40 Alcohol Evaporator
41 Combo Tank Installation for Regeneration-Style Air Dryers
42 Combo Tank Installation for Regeneration-Style Air Dryers
43 Meritor WABCO System Saver Series Single Cartridge Air
Dryer Component Replacement Guide — Dedicated
Purge
44 Meritor WABCO System Saver Series Single Cartridge Air
Dryer Component Replacement Guide
45
Section 7: Appendix IV — Exploded View of
System Saver 1200 Plus Series Air Dryer
46 Section 8: Appendix V — Temporary Air
Dryer Bypass
Bypass Procedure
47
Section 9: Appendix VI — Exploded View of
System Saver 1200 Plus Series with Multi
Circuit Protection
24
Section 3: Troubleshooting and Testing
Maintenance
25 Maintenance Tips
26 Troubleshooting
31 Tests
Heater Resistance
Electric Power to Dryer
Leak Test
Air Pressure Checks
Operational Test for System Saver Series Air Dryers —
Regeneration and Purge Style
32 Pressure-Controlled Check Valve Test — Regeneration
Style Only
34
Section 4: Appendix I — Glossary
Definitions
Basic Air System/Air Dryer Terms
Notes
1 Introduction
1 Introduction
Overview
Maintenance Manual 34 contains troubleshooting steps and service
information for the Meritor WABCO System Saver Series (1200 and
1800) single cartridge air dryers.
NOTE: If you have a System Saver TWIN air dryer, use Maintenance
Manual 35, Meritor WABCO System Saver TWIN Air Dryer. To obtain
this publication, refer to the Service Notes page on the front inside
cover of this manual.
Other Publications Related to Meritor WABCO
System Saver Series Single Cartridge Air
Dryers
TP-92116, Installing the Meritor WABCO System Saver Series Air
Dryer, provides complete installation instructions.
PB-8857AS contains a complete listing of air dryer replacement
parts.
TP-97101 is a troubleshooting guide. There is also a poster-sized
troubleshooting guide, TP-9772, available.
TP-9672, Air Dryer Application Guide, provides an in-depth look at
System Saver Series air dryer applications.
T-20102V, Air System Troubleshooting video Stopping With Air and
T-97105V, System Saver 1200 videotapes are also available.
Air Dryer Identification
Alphabetical designations of the System Saver Series family of air
dryers have specific meanings:
P Indicates an external purge tank is used for desiccant
regeneration
U Indicates discharge line — unloaded compressor
E Indicates a Holset style compressor function
G Indicates integral governor for air compressor control
UP Indicates discharge line — unloaded compressor (with external
purge tank)
System Saver 1200/1800: System regeneration valve assembly on
side of dryer
System Saver 1200E: Tubing and banjo fitting at front of dryer
System Saver 1200P/1800P: Uses dedicated purge tank. Port 22
drilled and tapped
System Saver 1200U/1800U: Small regeneration hole visible in
back of Port 1 when fitting is removed. No spring in turbo cut-off
valve assembly.
System Saver 1200UP/1800UP: Port 22 drilled and tapped. Small
regeneration hole visible at back of Port 1 when fitting is removed.
No spring in turbo cut-off valve assembly. Dedicated purge tank.
TP-1033, System Saver 1200 Plus Series Air Dryers, provides
installation instructions.
TP-1343, Troubleshooting and Repairing System Saver 1200 Plus
Air Dryers with Turbo Cut-off Valves on Vehicles with Cummins
Engines, provides service instructions.
TP-09133, Replacing a Bendix AD9 Air Dryer with a System Saver
1200 Plus Air Dryer, provides replacement instructions.
TP-0579, Installation Instructions for Meritor WABCO’s Dessicant
Cartridge Replacement Kit, provides installation instructions.
TP-9610, Using an Alcohol Evaporator with Meritor WABCO System
Saver 1000, 1200, and 1200 E Series Single Cartridge, provides air
dryer instructions.
TP-9557, Pressure Relief Valve Installation Instructions for Meritor
WABCO System Saver 1000, 1200 and 1200E Series and System
Saver TWIN Air Dryers, and Modification Instructions for Units
Equipped with Alcohol Evaporators, provides installation
instructions.
To order literature, visit our website at meritorwabco.com.
The air dryer base is the same for both the 1200 and 1800 Series
air dryers, however the 1800 Series canister is 3.2 inches taller
than the 1200. This larger canister contains 50% more desiccant,
which makes the 1800 ideal for applications calling for frequent
starts, stops and long compressor cycles. System Saver 1200 and
System Saver 1800 Series air dryers are illustrated in Figure 1.1.
System Saver 1200P and System Saver 1800P, which are used with
a dedicated purge tank, are illustrated in Figure 1.2.
System Saver 1200 Plus: Has the governor integrated into the
body of the air dryer and also has an integrated purge tank.
Figure 1.3.
System Saver 1200 Plus MCP: Has the governor and pressure
protection elements integrated into the body of the air dryer. Also
has an integrated purge tank. Figure 1.4.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
1
1 Introduction
4003875a
4003876a
4007638a
Figure1.1
SYSTEM SAVER 1200 AND 1800 SERIES
Figure 1.1
Figure1.2
Figure1.4
4011898a
SYSTEM SAVER 1200P AND 1800P
Figure 1.2
Figure1.3
SYSTEM SAVER 1200 PLUS MCP
Figure 1.4
How the Air Dryer Works
During system pressure build-up, compressed air passes into the air
dryer where the filter system removes contaminants and passes the
air into the drying stage.
Moisture-laden air passes through the desiccant bed in the air dryer
cartridge and moisture is retained by the desiccant. Moisture that
condenses out also collects in the base of the dryer. When the
compressor unloads, the water is expelled and dried air flows back
through the dryer, drying the desiccant for the next cycle.
NOTE: For further information about System Saver E air dryers and
components, refer to Section 4 and Section 5. For special
applications, refer to Section 6.
SYSTEM SAVER 1200 PLUS
Figure 1.3
2
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Air Dryer Cycle
1002142a
CONTROL
“WET” AIR
“DRY” AIR
CONTROL/DRY
LINES
ENGINE TURBO
BOOST PRESSURE
1002143a
1002145a
CONTROL
“WET” AIR
“DRY” AIR
CONTROL/DRY
LINES
ENGINE TURBO
BOOST PRESSURE
A single cartridge air dryer cycle is illustrated in Table A.
Table A
The governor turns the compressor on when supply tank pressure
drops below cut-in pressure, between 100 psi and 110 psi
(689-758 kPa) depending on governor settings.
Compressed air passes into the air dryer at the inlet port:
앫 Moisture-laden air and contaminants pass through the
desiccant.
1 Introduction
앫 Moisture is retained by desiccant; moisture also collects in the
base of the dryer.
앫 Contaminants are removed as air passes through the desiccant
bed.
The governor turns the compressor off when system reaches
cut-out pressure, between 120 psi and 130 psi (827-896 kPa)
depending on governor settings.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
3
1 Introduction
1002144b
1200E, P, U
1800E, P, U
1200 PLUS
TO
CANISTER
FROM
CANISTER
IN
OUT TO TANKS
When the compressor unloads, the purge valve opens:
앫 On 1200E, P, U, 1800E, P, U, the dryer purges the desiccant
cartridge and expels any water collected in the dryer base.
— Regeneration valve opens.
앫 On 1200 regeneration models, when the regeneration valve
opens.
— Dry system air flows back through the dryer, 10 psi (69 kPa)
is taken from the supply and secondary tanks for the
regeneration.
— Back flow dries desiccant, preparing it for the next cycle.
앫 On 1200 P, UP, 1800 P and UP:
— Dry air flows from the separate purge tank back through the
air dryer.
앫 On 1200 Plus:
— Dry air flows from the integrated purge tank back through
the air dryer. Air can be felt and heard flowing from the
purge valve for an extended period of time.
— Dry system air flows back through the air dryer to
regenerate the desiccant.
4
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Typica l System
1002141c
PURGE
VA LV E
(EXHAUST)
COMPRESSOR
DISCHARGE
LINE
COMPRESSOR
CONTROL
(PURGE) PORT
COMPRESSOR
INTAKE LINE
PRESSURECONTROLLED
CHECK VALVE
SUPPLY
TANK
SYSTEM
RESERVOIRS
ONE-WAY
CHECK
VA LV E
DRYER
OUTLET
PORT
SYSTEM SAVER SERIES
REGENERATION
STYLE AIR DRYER
DRYER
INLET
PORT
UNLOADER
LINE
RESERVOIRTO-GOVERNOR
LINE
1800
1200
SUPPLY
LINE
PURGE
TANK
PURGE
VA LV E
(EXHAUST)
P SERIES WITH DEDICATED
PURGE TANK
BOTTOM VIEW
OF AIR DRYER
REGENERATION
VA LV E
GOVERNOR
UNLOADER
PORT
A typical Meritor WABCO System Saver 1200 or 1800 Series air
dryer installation is illustrated in Figure 1.5. A System Saver 1200
Plus system is shown in Figure 1.6. Illustrations for Combo Tank
installations appear in Section 6.
Figure1.5
1 Introduction
Figure 1.5
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
5
1 Introduction
4012522a
COMPRESSOR
DISCHARGE
LINE
PURGE VALVE
(EXHAUST)
COMPRESSOR
CONTROL
(PURGE)
PORT
DRYER
INLET PORT
COMPRESSOR
INTAKE LINE
SUPPLY
TANK
SYSTEM
RESERVOIRS
ONE-WAY
CHECK
VA LV E
SYSTEM SAVER
1200 PLUS
AIR DRYER
UNLOADER
LINE
SUPPLY
LINE
Figure1.6
Figure 1.6
6
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Air Dryer Components
1002146b
SYSTEM SAVER 1200 OR 1800
COALESCING DESICCANT
CARTRIDGE
PRESSURE
RELIEF
VA LV E
PURGE
VA LV E
ASSEMBLY
REGENERATION VALVE ASSEMBLY
(FOR REGENERATION STYLE AIR
DRYERS)
O-RING
12- OR 24-VOLT
HEATER ASSEMBLY
1200
1800
PURGE
TANK
Port 22 drilled
and tapped for
dedicated purge
style.
TURBO
CUT-OFF
VA LV E
ASSEMBLY
OUTLET
CHECK
VA LV E
ASSEMBLY
Meritor WABCO single cartridge air dryers contain replaceable
component parts. Standard air dryer components are illustrated in
Figure 1.7. For 1200 Plus Series air dryers, refer to Figure 1.8.
Refer to Figure 1.9 for 1200 Plus Series air dryers with Multi Circuit
Protection. Refer to Section 2 for instructions for removal of old
parts and installation of new parts.
Figure1.7
1 Introduction
Figure 1.7
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
7
1 Introduction
4007692a
PRESSURE
RELIEF
VA LV E
DESICCANT
CARTRIDGE
SYSTEM SAVER 1200 PLUS SERIES AIR DRYER
OUTLET
CHECK
VA LV E
ASSEMBLY
GOVERNOR
O-RING
PURGE VALVE
ASSEMBLY
TURBO
CUT-OFF
VA LV E
ASSEMBLY
HEATER
ASSEMBLY
Figure1.8
Figure 1.8
8
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
1 Introduction
4011774a
PURGE VALVE
ASSEMBLY
HEATER ASSEMBLY
GOVERNOR
OUTLET CHECK
VALVE ASSEMBLY
O-RING
TURBO
CUT-OFF
VA LV E
ASSEMBLY
PRESSURE
RELIEF VALVE
DRAIN
VA LV E
DESICCANT
CARTRIDGE
SYSTEM SAVER 1200 PLUS SERIES AIR DRYER
WITH MULTI CIRCUIT PROTECTION
Figure1.9
Figure 1.9
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
9
1 Introduction
1002148b
1800
1200
Dryer Identification
The identification tag on the face of the dryer provides important
information about the air dryer — information you will need when
servicing or replacing components. Figure 1.10.
Figure1.10
SYSTEM
SAVER
1200 PLUS
SYSTEM
SAVER
1200E
SYSTEM
SAVER
1800/1800U
SYSTEM
SAVER
1200P/1200UP
OR
1800P/1800UP
SYSTEM
SAVER
1200/1200U
1696
Figure 1.10
Description of Components
Replacement components for single canister air dryers are
described below.
Desiccant Cartridge: A cylindrical steel housing containing the
filter elements and desiccant needed to filter and dry system air.
Spin-on/spin-off design allows quick and easy maintenance. The
System Saver 1800 Series cartridge is 3.2-inches (81 mm) taller
than the 1200 Series cartridge [6.4-inches (164 mm) tall].
Figure 1.11.
Always replace cartridges with authentic Meritor WABCO brand
cartridges.
Figure1.11
MANUFACTURING
LOCATION CODE
DATE CODE
FIRST TWO DIGITS = BUILD WEEK
LAST TWO DIGITS = BUILD YEAR
PA RT
NUMBER
1002147c
10
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Figure 1.11
1 Introduction
1002149a
HEATER MAY BE STAINLESS
STEEL CLAD OR CERAMIC
1002150a
1002151a
1002152b
AIR FLOW
DIRECTION
1002153a
Coalescing Cartridge: Utilizes a filter element added to the
standard desiccant to remove aerosols and oil particles.
Heater: Located in the air dryer base, the heater prevents water
that collects in the air dryer from freezing. It consists of a cylindrical
resistive-type heating element and a small circular thermostat.
Heater is available for 12- and 24-volt air dryers. Figure 1.12.
Figure1.12
Figure 1.12
Bypass Valve: A valve located between the inlet and outlet ports of
the dryer. It allows air to flow into the dryer and go directly to the
outlet port, bypassing the desiccant cartridge. The 1200 and 1200E
Series with date codes later than 0894 do not use a bypass valve.
Figure 1.13.
Figure1.14
Figure 1.14
Pressure-Controlled Check Valve (PCCV): Used with System
Saver Series regeneration style air dryers. The PCCV is usually
mounted on the secondary air tank in place of an inlet check valve. It
lets air backflow from the secondary tank to the supply tank as long
as system pressure remains between the normal cut-in and cut-out
range of the governor. It allows additional air volume for generation
during the air dryer purge cycle. Not used with integrated or
separate purge tank style air dryers. Figure 1.15.
Figure1.15
Figure1.13
Figure 1.13
Outlet Check Valve: A valve located in the outlet port (port 21) of
the air dryer. It prevents air from flowing back through the air dryer
and escaping out the purge valve during a compressor unload cycle.
Figure 1.14.
Figure 1.15
Pressure Relief Valve: A valve that protects the air dryer from
over-pressurization. On dryers with date codes earlier than 2295, it
is installed in the inlet port of the dryer (port 1) using a Street-Tee
fitting. On dryers with date codes later than 2295, the pressure
relief valve is attached directly to the air dryer. Figure 1.16.
Figure1.16
Figure 1.16
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
11
1 Introduction
1002154a
1002155a
4003877a
4003878a
Purge Valve: A valve located on the bottom of the air dryer base
that remains open during a compressor unload cycle. It allows
collected moisture, condensation, and contamination to be expelled
from the air dryer during a purge cycle. Figure 1.17.
Figure1.17
Figure 1.17
Regeneration Valve: The valve that controls regeneration of the
desiccant. It allows air from the supply and secondary tanks to
bypass the outlet check valve. The air expands and backflushes
moisture off of the desiccant, then out through the dryer’s purge
valve. Figure 1.18.
ECON Valve Replacement Part: This valve is used on System
Saver Series 1200E single cartridge air dryers used with Holset
E-type compressors. Figure 1.19.
Figure1.19
Figure 1.19
ECON Valve: This valve must be installed if System Saver 1200
Series air dryers NOT DESIGNATED E are used with Holset E-type
compressors. This valve is not required on System Saver 1200 E air
dryers. Figure 1.20.
Figure1.20
Used with 1200 Series air dryers only.
Figure1.18
Figure 1.18
Figure 1.20
Turbo Cut-off Valve: A valve located in the inlet port of the air dryer.
It closes the path between the air compressor and the air dryer
purge valve during compressor unload. This prevents a loss of
turbocharger boost pressure during a compressor unload cycle,
thereby maintaining boost pressure for maximum engine
horsepower. Figure 1.21 and Figure 1.22 (used exclusively on the
1200 Plus model).
There is no spring in the turbo cut-off valve assemblies used on U
Series air dryers.
The System Saver E Series air dryers use a special turbo cut-off
valve. Refer to the air dryer parts book PB-8857AS for part number
information.
12
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
1 Introduction
1002156a
TOP
SPRING
4007691a
SYSTEM SAVER
1200 PLUS
1002157a
1002158a
Figure1.21
Figure 1.21
Figure1.22
Figure1.24
Figure 1.24
Pressure Protection Elements: Ports that are located directly on
the air dryer. The eight ports are directly connected to the primary,
secondary and any auxiliary air tanks. The function of the pressure
protection elements is to protect the air tanks from a loss of
pressure in the air system. These pressure protection elements are
not serviceable. Figure 1.25.
Figure1.25
Figure 1.22
Heater Power Harness: Twelve-inch cable with Metri-Pack plug
provides electrical connection to air dryer heating unit. Figure 1.23.
Figure1.23
4011899a
Figure 1.23
Figure 1.25
Purge Silencer: Optional part for all Meritor WABCO air dryers. It is
used to reduce the noise level of an air dryer purge. Figure 1.24.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
13
2 Component Removal and Installation
WARNING
2 Component Removal and Installation
Hazard Alert Messages
Read and observe all Warning and Caution hazard alert messages in
this publication. They provide information that can help prevent
serious personal injury, damage to components, or both.
To prevent serious eye injury, always wear safe eye protection
when you perform vehicle maintenance or service.
Remove all pressure from the air system before you
disconnect any component, including the desiccant cartridge.
Pressurized air can cause serious personal injury.
Park the vehicle on a level surface. Block the wheels to
prevent the vehicle from moving. Support the vehicle with
safety stands. Do not work under a vehicle supported only by
jacks. Jacks can slip and fall over. Serious personal injury and
damage to components can result.
Table B
Replacement Requirements
NOTE: The pressure protection elements are not serviceable on the
System Saver 1200 Plus with MCP. The entire air dryer needs to be
replaced if these parts are not operating effectively.
Component Replacement
Requirements
Refer to Table B for component replacement requirements. If
necessary, you may also refer to Table D for System Saver Series air
dryer troubleshooting. Before replacing any air dryer component,
verify that the air compressor and air governor are working correctly,
then drain the air tanks. Repair or replace these parts, if necessary.
Check the entire air system for leaks, and repair as necessary.
When draining air tanks before servicing the air dryer, check for
water and/or oil that may have accumulated in the tanks. Water
and/or oil in the air tanks could indicate a problem with the dryer or
compressor.
Component When to Replace Why
Cartridge Every two to three years for standard dessicant.
Every one to two years for coalescing.
When compressor is replaced. Contaminated cartridge.
Water in supply tank. Saturated or contaminated cartridge, high duty cycle
Bypass Valve (dryers with date
codes earlier than 0894)
Heater Assembly Water collecting in air dryer is freezing —
Outlet Check Valve Air continues to flow from purge valve after
Purge Valve No purge cycle when compressor unloads —
Valve leaking, inlet to outlet. Cut O-ring, bad seat.
electrical power to dryer is O.K.
purge cycle, but stops flowing when the
compressor load cycle begins.
No pressure build-up in system, everything else
is O.K.
normal pressure at dryer control port 4 (governor
port).
Air flows from purge valve during compressor’s
load cycle — no pressure at dryer control port.
Preventative maintenance.
(wrong application of air dryer).
Heater assembly not working (internal short or open
circuit).
Valve is stuck in the open position, or not functioning
properly.
Valve is stuck in closed position.
Valve is stuck in the closed position, or not
functioning properly.
Valve is stuck in the open position, or not functioning
properly.
Pressure Protection Valve Pressure protection valves will not open (air
dryer must be replaced).
14
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Valves are stuck in closed position.
2 Component Removal and Installation
1002163b
1800
1200
Replacement Requirements
Component When to Replace Why
Turbo Cut-Off Valve Air compressor stuck pumping, TCU remains
open. System will build pressure until safety
valve opens in system.
Signal line loss.
Air flows from purge valve during compressor
unload cycle after purge cycle, and flow is
noticeably stronger at high engine RPM,
especially under load.
No pressure build-up in system — high
compressor discharge line pressure.
Regeneration Valve Regeneration cycle continues after compressor
begins, and secondary tank pressure drops 15
psi (103 kPa) or more.
Purge cycle is too short (five seconds or less) —
pressure-controlled check valve is O.K., no leak
in governor control line.
Air dryer purges — but no regeneration, no
check valve between air dryer and supply tank,
and purge valve has not closed.
Pressure-Controlled Check
Valve
NOTE: When replacing air dryer components, use only Meritor
Regeneration cycle too short; may result in
water in tank.
Figure2.1
WABCO replacement parts.
Turbo cut-off valve leaking.
Valve stuck in closed position.
Regeneration valve allowing too much air to come
back into cartridge.
Regeneration valve not allowing enough air to come
back into cartridge.
Regeneration valve not allowing any air to come back
into cartridge.
Valve checks (stops airflow) too high.
The exploded view of the air dryer in Section 1 shows the location of
the various air dryer components.
Component Removal and Installation
Desiccant Cartridge
NOTE: Replacement cartridges are marked “System Saver
Series.”
1. Replacement kit contains one cartridge and one O-ring.
Figure 2.1.
Figure 2.1
2. Loosen and remove the old cartridge. Use strap wrench if
necessary.
3. Remove and discard O-ring from dryer base.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
15
2 Component Removal and Installation
1002164a
SEAL
SEAL SEAT
O-RING
1002165a
O-RING
SPRING
GREASE
WASHER
SNAP
RING
VA LV E
BODY
1002166a
SNAP RING
WASHER
SPRING
O-RING
VA LV E
BODY
1002167a
THERMOSTAT
RECEPTACLE
O-RING
HEATER
ELEMENT
NOTE: If seats are damaged so badly that a tight seal cannot
be maintained, replace the air dryer.
4. Inspect and clean seal seat. Repair any minor damage.
5. Lubricate and install new O-ring on stem.
6. Lubricate cartridge seal.
7. Thread replacement cartridge onto the base until the seal
touches the base. Then, tighten the cartridge ONE additional
turn. DO NOT OVERTIGHTEN. Figure 2.2.
Figure2.2
2. Remove the snap ring, washer, spring, valve body and O-ring.
3. Clean and inspect the valve bore. If the bore is damaged so
that a tight seal cannot be maintained, replace the air dryer.
4. Install the new O-ring on the valve body. Figure 2.4.
Figure2.4
Figure 2.4
5. Apply a thin layer of grease to the valve bore and the O-ring.
6. Install the new valve body with its long end in the bore.
7. Install the new spring with its small end around the “Y”-shaped
fins on the valve body.
Figure 2.2
Outlet Check Valve Assembly
1. Review Figure 2.3 to ensure you have all of the parts required
to replace the outlet check valve. Use the grease included with
the replacement kit to lubricate the O-ring seal.
Figure2.3
Figure 2.3
8. Install the new washer and the new snap ring to hold the
components in place.
Heater Assembly
1. Review Figure 2.5 to ensure you have all of the parts required
to replace the heater assembly.
Figure2.5
Figure 2.5
2. Disconnect the plug.
16
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
2 Component Removal and Installation
1002168a
O-RING
HEATER
ELEMENT
THERMOSTAT
RECEPTACLE
1002170b
PISTON
SPRING
COVER
3. Remove the screws, receptacle and O-ring from the base to
access the retainer screw.
4. Remove the retainer screw and then remove the entire heater
assembly.
5. Install the O-ring to heater connector housing.
6. Install the new element and thermostat in their cavities.
NOTE: For dryers with date codes of 0894 or earlier, follow the
special instructions in the replacement kit to complete the
installation.
7. Install the new retainer and screw to hold the element and the
thermostat in place.
8. Install the receptacle and fasten them in place with the screws.
Figure 2.6.
Figure2.6
Figure2.7
LIP SEAL
Spring not used in
U Series air dryers.
GREASE
SNAP RING
CAP
Figure 2.7
PISTON
SPRING
O-RING
COVER
1002169a
2. Remove the snap ring. The cover and spring may fall out of the
bore when the snap ring is removed.
Figure 2.6
Turbo Cut-Off Valve Assembly
NOTE: E Series air dryers use a different turbo cut-off valve
assembly. Refer to parts book PB-8857AS, Anti-Lock Brake
Systems and Air Systems Parts. To obtain this publication, refer to
the Service Notes page on the front inside cover of this manual.
NOTE: Use the grease included with the replacement kit to lubricate
O-rings and seals.
System Saver 1200/1800 Series Turbo Cut-Off Valve
Assembly
1. Review Figure 2.7 to ensure you have all of the parts required
to replace the turbo cut-off valve.
3. Use needle nose pliers to remove the piston. Figure 2.8.
Figure2.8
Figure 2.8
4. Clean and inspect the valve bore. If the bore is damaged so
that a tight seal cannot be maintained, replace the air dryer.
Figure 2.8.
5. Install new lip seal on piston. Seal lip must face up (toward top
of piston).
NOTE: Kits made after 12-1-09 use an O-ring in place of a lip
seal.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
17
2 Component Removal and Installation
4007926a
PISTON
SLEEVE
COVER
SNAP
RING
6. Install new O-ring on cover.
7. Apply a thin layer of grease to the valve bore and the O-rings.
8. Install the new piston with flat side toward dryer.
9. Install the new spring, cover and snap ring to hold the
components in place.
10. Install the plug.
11. Replace the desiccant cartridge.
System Saver 1200 Plus Turbo Cut-Off Valve
Assembly
1. Remove the snap ring. Figure 2.9.
Figure2.9
System Saver 1200 Plus Governor
Function— The governor controls the cut-in and cut-out pressure
of the compressor through signal lines from the system reservoir as
well as the compressor head controlling onload and offload.
Use only the Meritor WABCO governor specified for use with the
System Saver 1200 Plus air dryer.
NOTE: Some models have O-rings instead of a gasket.
1. Remove the mounting bolts, governor and gasket or O-rings.
Discard the gasket or O-rings. Figure 2.10.
Figure2.10
AIR DRYER
BOLT
GASKET
GOVERNOR
4007927a
Figure 2.9
2. Remove the cover.
3. Remove the piston and sleeve.
4. Clean and inspect the valve bore. If the bore is damaged so
that a tight seal cannot be maintained, replace the air dryer.
5. Apply a thin layer of grease to the valve bore and the O-rings.
6. Install new O-rings on the piston and sleeve.
7. Press the piston into the sleeve.
8. Press the piston-sleeve assembly into the air dryer.
9. Install the cover and snap ring.
10. Replace the desiccant cartridge using the detailed instructions
provided earlier in this section.
Figure 2.10
2. Place the governor and a new gasket or O-rings into position
on the air dryer.
3. Install the mounting bolts and tighten to 14.75 ft-lb (20 N폷m).
@
Regeneration Valve Assembly
The regeneration valve assembly kit contains two different
diaphragms to service the regeneration valve assembly for System
Saver 1200 or 1800 air dryers. Use the correct diaphragm for the
style of regeneration valve housing as indicated in the sketches
below. Use of the incorrect part will result in unsatisfactory purging
of the desiccant cartridge and may result in excess water in the air
system.
1. Review Figure 2.11 to ensure you have all of the parts required
to replace the regeneration valve. Use the grease included with
the replacement kit to lubricate O-rings and seals.
18
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
2 Component Removal and Installation
INCLUDED IN KIT
DIAPHRAGM
DIAPHRAGM
CAP
SPRING
VA LV E
HOUSING
VA LV E
HOUSING
CAP
SPRING
The smooth diaphragm is
used with the smooth,
cylindrical regeneration
valve housing.
INCLUDED IN KIT
The speckled/dotted
diaphragm is used
with the finned/
ribbed die cast
housing.
Only one diaphragm is used per assembly.
DO NOT GREASE THE DIAPHRAGM.
4003879a
1002172a
DIAPHRAGM
SPRING
VA LV E
HOUSING
ASSEMBLY
CAP
1002173b
METAL SHIMS
(IF REQUIRED)
O-RING
WASHER
O-RING
PISTON
SPRING
O-RING
VA LV E
HEAD
WASHER
GREASE
SNAP RING
Figure2.11
Figure2.12
Figure 2.12
Purge Valve Assembly
1. Review Figure 2.13 to ensure you have all of the parts required
to replace the purge valve.
Use the grease included with the replacement kit to lubricate
O-rings and seals. Do not grease the rubber seat.
Figure 2.11
2. Remove the four mounting bolts and the valve housing
assembly. When you remove the housing, the spring and cap
will fall out.
3. Remove the rubber diaphragm.
4. Clean and inspect the diaphragm lip groove. If the groove is
damaged so that a tight seal cannot be maintained, replace the
air dryer.
5. Install the new diaphragm with its lip in the groove. DO NOT
GREASE THE DIAPHRAGM.
6. Install the new spring and cap with the cap lip facing out. Install
the valve housing assembly with the new lubricated O-ring and
filter over the orifice. Install the new mounting bolts and tighten
to 53 in-lb (6 N폷m). Figure 2.12.
@
If shims are included in the replacement kit, they must be
installed above and below the spring. If they are not included,
they are not needed.
Figure2.13
Figure 2.13
2. Remove the snap ring, valve head and spring.
3. Remove the piston assembly from the base. Figure 2.14.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
19
2 Component Removal and Installation
WARNING
1002174a
SPRING
VALVE HEAD
PISTON
ASSEMBLY
1002175b
LIP
1002176a
Figure2.14
Figure 2.14
4. Remove washer and O-rings from the base.
5. Clean and inspect the valve bore. If the bore is damaged so
that a tight seal cannot be maintained, replace the air dryer.
6. Apply a thin layer of grease to the valve bore and to all O-rings
(use the grease included with replacement kit).
7. Install new washer and O-ring in dryer base and on valve head.
9. Install washer on piston assembly. Figure 2.16.
Figure2.16
Figure 2.16
10. Install spring in valve head; fit valve head assembly into bore.
NOTE: If shims are included in the replacement kit, they must
be installed above and below the spring. If they are not
included, they are not needed.
11. Install snap ring to hold the valve head in place.
NOTE: Lip on washer must face piston seat. Figure 2.15.
8. Assemble the piston assembly,
앫 Install O-ring in groove on piston head.
앫 Install piston seat in groove on piston base.
앫 Install washer on piston.
Figure2.15
Figure 2.15
NOTE: Make sure the snap ring is fully seated or assembly will
leak from the purge valve.
Pressure-Controlled Check Valve (PCCV)
Remove all air pressure from the tank before you remove the
pressure-controlled check valve. Pressurized air can cause
serious personal injury.
NOTE: New style valves have the hex nipple pipe fitting
installed.
1. Before replacing, look at the arrow on this valve. You must
install the valve so that the arrow faces the tank on which it is
installed. Figure 2.17.
20
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
2 Component Removal and Installation
1002177b
PRESSURE-CONTROLLED
CHECK VALVE
TANK
HEX NIPPLE
PIPE FITTING
Arrow on
bottom of
valve must
face tank.
AIR LINE
0894
DATE
CODE
1002178a
1002179a
SNAP
RING
O-RING
VA LV E
BODY
SPRING
O-RING
COVER
1002180a
SNAP
RING
VA LV E
BODY
SPRING
COVER
Figure2.17
Figure 2.17
2. Disconnect the air line from the pressure-controlled check
valve and remove the valve from the tank and hex nipple pipe
fitting.
3. Install the new valve.
앫 Whatever orientation (up or down) the valve is in when it is
tight is acceptable, as long as the arrow is pointing toward
the tank.
4. Apply pipe sealant to the fittings and connect the air line to the
PC check valve.
5. Test the installation for proper operation. Refer to the
procedure in this section.
Use the grease included with the replacement kit to lubricate
O-rings and seals.
Figure2.19
Figure 2.19
2. Remove the snap ring, cover, spring and valve body.
3. Clean and inspect the valve bore. If the bore is damaged so
that a tight seal cannot be maintained, then replace the air
dryer.
4. Install the new O-rings on the new valve body and cover.
5. Apply a thin layer of grease to the valve bore and the O-rings.
6. Install the new valve body with its long end in the bore.
Figure 2.20.
Figure2.20
Bypass Valve
NOTE: The bypass valve is used on dryers with date codes of 0894
or earlier. Figure 2.18.
Figure2.18
Figure 2.18
1. Review Figure 2.19 to ensure you have all of the parts required
to replace the bypass valve.
Figure 2.20
7. Install the new spring so it fits around the “Y”-shaped fins on
the valve body.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
21
2 Component Removal and Installation
WARNING
1002181b
PORT 1
PRESSURE
RELIEF VALVE IN
STREET-TEE FITTING
PORT 31
PRESSURE
RELIEF VALVE
1002182a
PORT 1
± 30º
1002183a
PURGE
VA LV E
HEAD
SILENCER
8. Install the new cover and the new snap ring to hold the
components in place.
Pressure Relief Valve
NOTE: If you plan to replace the Street-Tee fitting, refer to
TP-9557, Pressure Relief Valve Installation, for instructions. To
obtain this publication, refer to the Service Notes page on the front
inside cover of this manual.
1. Remove the old valve from the dryer.
If your dryer uses a bypass valve (date code of 2295 or earlier),
the pressure relief valve will be installed with a Street-Tee
fitting at the front (Port 1) of the dryer. On dryers with date
codes later than 2295, the pressure relief valve is located at
the side of the dryer (Port 31). Figure 2.21.
Figure2.21
Do not exceed torque of 30 ft-lb (40.8 N폷m) for 3/8-inch
thread, or 65 ft-lb (88.4 N폷m) for 1/2-inch thread.
Figure2.22
Figure 2.22
Purge Silencer (Muffler)
@
Figure 2.21
2. Unscrew and remove the old pressure relief valve. Figure 2.21.
For Street-Tee installations, install the pressure relief valve in
the UP position, or within 30° of vertical. Figure 2.22. If not
installed in the correct position, serious personal injury and
damage can result.
NOTE: The threads on the replacement pressure relief valve
provided by Meritor WABCO are coated with sealant. They do
not require any additional sealant.
3. Screw the replacement valve into the Street-Tee fitting or the
dryer base, depending on the date code of the air dryer.
NOTE: This is an optional part designed to reduce dryer purge noise
level.
1. Remove retainer ring. Remove old silencer from purge valve
head. Do not damage purge valve head.
2. Clean purge valve head.
3. Install replacement silencer firmly onto purge valve head until
fully seated. Secure with retainer ring. Figure 2.23.
Figure2.23
Figure 2.23
22
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
2 Component Removal and Installation
1002184b
1002185b
4012519a
Air Dryer Assembly
NOTE: This procedure is for removing and replacing a unit. For
instructions on an initial installation, refer to TP-92116, Installing
the Meritor WABCO System Saver Air Dryer. To obtain this
publication, refer to the Service Notes page on the front inside cover
of this manual.
1. Drain all pressure from the air system. Disconnect all air lines.
Use markers to label the lines for proper reinstallation.
2. Disconnect the heater electrical plug from the heater
receptacle.
3. Remove the three mounting bolts. Remove the air dryer from
its mounting location. Figure 2.24 and Figure 2.25.
Figure2.24
4. Attach the new unit to the frame or mounting bracket with new
mounting capscrews and washers. Tighten the capscrews to
22-30 ft-lb (30-40 N폷m). Figure 2.26 and Figure 2.27.
Figure2.26
SYSTEM SAVER SERIES SHOWN
Figure 2.26
Figure2.27
@
SYSTEM SAVER SERIES SHOWN
Figure 2.24
Figure2.25
SYSTEM SAVER 1200 PLUS SERIES SHOWN
Figure 2.25
4012518a
SYSTEM SAVER 1200 PLUS SERIES SHOWN
Figure 2.27
5. Connect heater electrical plug to heater receptacle.
6. Reconnect all system air lines.
7. Test the installation for correct operation. Refer to the
procedure in this section.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
23
3 Troubleshooting and Testing
WARNING
3 Troubleshooting and Testin g
Hazard Alert Messages
Read and observe all Warning and Caution hazard alert messages in
this publication. They provide information that can help prevent
serious personal injury, damage to components, or both.
To prevent serious eye injury, always wear safe eye protection
when you perform vehicle maintenance or service.
Remove all pressure from the air system before you
disconnect any component, including the desiccant cartridge.
Pressurized air can cause serious personal injury.
Park the vehicle on a level surface. Block the wheels to
prevent the vehicle from moving. Support the vehicle with
safety stands. Do not work under a vehicle supported only by
jacks. Jacks can slip and fall over. Serious personal injury and
damage to components can result.
NOTE: The pressure protection elements are not serviceable on the
System Saver 1200 Plus with MCP. The entire air dryer needs to be
replaced if these parts are not operating effectively.
Maintenance
To keep your Meritor WABCO air dryer operating efficiently, the
routine maintenance in Table C is recommended.
Table C
Action Interval
Ensure the dryer purges when compressor unloads. Weekly.
Drain the purge tank (dedicated purge tank dryers). Weekly, or as recommended by the manufacturer.
Check for moisture in the system by opening the drain cock on vehicle
system reservoirs slowly.
Replace the standard desiccant cartridge. Every two to three years, or more often depending on usage,
Replace the coalescing cartridge. Every one to two years.
Weekly, or as recommended by the manufacturer, whichever is
most frequent.
vocation, and condition of compressor.
Whenever compressor is rebuilt.
24
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Maintenance Tips
1002159a
With proper maintenance, the Meritor WABCO air dryer will provide
years of reliable service, even under adverse operating conditions.
To provide additional protection against the harmful effects of
extreme heat or cold, here are a few helpful tips.
Dedicated Purge Tank
Optimum mounting location for the dedicated purge tank is above
the air dryer.
Extreme Heat
Make sure the compressor discharge line is long enough to keep
inlet air below 175°F (80°C). Figure 3.1. (Refer to Section 5.)
Figure3.1
3 Troubleshooting and Testing
Figure 3.1
Extreme Cold
Make sure the air dryer heater is in good working order by running a
heater resistance test. Refer to the procedure in this section.
Check the line from the governor to port 4 of the dryer for oil and/or
water. Keep this line clean to help prevent freezing.
Meritor WABCO air dryer components are installed in the air dryer at
the factory and are designed to last for the life of the dryer. Under
some operating conditions, however, a replacement may be
required. Refer to Section 2 for replacement guide instructions.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
25
3 Troubleshooting and Testing
Troubleshooting
Conditions you may experience, and suggested solutions, appear in
Tab l e D.
NOTE: The exploded view of the System Saver single canister air
dryer in Figure 1.7 illustrates the location of components in the
dryer.
Table D: System Saver Series Air Dryer Troubleshooting
Conditions May Occur In:
Condition Possible Cause
Dryer leaks from
purge valve during
compressor loaded
cycle. The leak may
cause excessive
compressor cycling
or prevent the
system from
building air
pressure.
Regeneration cycle
too long (more than
30 seconds),
accompanied by loss
of pressure in the
supply tank.
Purge valve frozen open (cold
weather operation).
Debris under purge valve seat,
such as particles from fittings or
air inlet line.
Purge valve washer installed
upside-down.
Wrong air line connected to
dryer port 4 (unloader port).
Purge valve snap ring not fully
seated in groove.
Outlet check valve not seating. Yes Yes Inspect and replace outlet check valve
Regeneration valve not shutting
off regeneration airflow.
Regeneration
Style Air
Dryers
Yes Yes Check heater. Repair/replace if
Yes Yes Disassemble and clean purge valve.
Yes Yes Ensure lip on aluminum washer faces
Yes Yes Verify correct air line installation and
Yes Yes Seat snap ring fully into groove.
Yes No Replace regeneration valve.
Dedicated
Purge Tank
Air Dryers
Solution
necessary. Make sure governor to dryer
port 4 line is free of water/oil.
Remove and inspect purge valve and
clean water/oil from top of piston.
Remove cartridge and clean dryer sump
area.
DOWN, away from dryer.
correct as needed.
as needed.
26
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Conditions May Occur In:
3 Troubleshooting and Testing
Condition Possible Cause
Regeneration cycle
too short (less than
10 seconds).
High air system demands during
compressor unloaded cycle.
Pressure-controlled check valve
not installed in system or not
Regeneration
Style Air
Dryers
Yes Yes Increase air system capacity or reduce
Yes Yes Check and replace pressure-controlled
Dedicated
Purge Tank
Air Dryers
Solution
air demands.
check valve as needed.
working properly.
One-way check valve installed in
system reservoir instead of, or
with, pressure-controlled check
Yes No Remove one-way check valve. Make
sure pressure-controlled check valve is
installed correctly.
valve.
Regeneration valve not working. Yes No Remove regeneration valve and clean oil
from diaphragm. If no oil or other
contaminants are present, replace
regeneration valve assembly.
Air governor not working
properly.
Yes Yes Inspect air governor. Repair/replace per
manufacturer’s instructions.
Water in purge tank. Block in purge tank line. N/A Yes Clear blockage. Replace desiccant
cartridge.
No regeneration
cycle. No airflow
from purge valve
after initial purge
Air dryer not connected to
supply tank or connections
reversed at dryer.
Regeneration valve not working. Yes No Replace regeneration valve.
Yes No Verify proper dryer installation per
system diagram.
blast (dryer
decompression).
One-way check valve installed in
supply tank.
Yes No Remove one-way check valve.
Alcohol evaporator installed
between dryer and supply tank.
Blocked line/pinched line from
purge tank.
Air dryer does not
purge when
compressor unloads
(no blast of air from
Air line between governor and
air dryer port 4 kinked or
plugged.
Purge valve stuck closed. Yes Yes Replace purge valve.
purge valve).
Air governor not working
properly.
Cut-out pressure never achieved
by air compressor.
Yes No Install bypass line around evaporator or
remove evaporator from system.
No Yes Clear/repair line.
Yes Yes Repair air line.
Yes Yes Inspect air governor. Repair/replace per
manufacturer’s instructions.
Yes Yes Check for air leaks in system and repair
as needed. If no leaks in system, check
compressor output. Repair/replace per
manufacturer’s instructions.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
27
3 Troubleshooting and Testing
Conditions May Occur In:
Condition Possible Cause
Air dryer purges too
often, perhaps as
frequently as every
15 seconds,
Leak in line between governor
and dryer port 4.
Leak in line between supply tank
and governor.
accompanied by
excessive cycling of
the compressor.
Leaks in the air system. Yes Yes Repair leaks.
Excessive air system demands. Yes Yes Increase air system capacity or reduce
Outlet check valve not seating. Yes Yes Inspect and replace outlet check valve
Regeneration valve not shutting
off properly.
Air governor has less than 16
psi (110 kPa) range.
Leaking air compressor
unloader(s).
Air flows out of
purge valve entire
Turbo cut-off valve not sealing. Yes Yes Replace turbo cut-off valve.
Outlet check valve not seating. Yes Yes Replace outlet check valve.
time compressor is
unloaded.
Regeneration
Style Air
Dryers
Dedicated
Purge Tank
Air Dryers
Solution
Yes No Repair air line.
Yes Yes Repair air line.
air demand.
as needed.
Yes No Replace regeneration valve.
Yes Yes Replace air governor.
Yes Yes Inspect compressor. Repair/replace per
manufacturer’s instructions.
NOTE: With U Series
air dryers, the
compressor unloads
through the dryer, so a
steady flow of air is
normal.
Rapid “spitting” of
air from purge valve
in small amounts.
Frequency varies
with engine speed.
NOTE: With U Series
air dryers, the
compressor unloads
through the dryer, so a
steady flow of air is
normal.
Holset E-type compressor used,
but no Econ valve installed.
Compressor not completely
unloading when cut-out
pressure is reached.
Yes Yes Install Econ valve to provide make-up air
to compressor.
Yes Yes Inspect compressor. Repair/replace per
manufacturer’s instructions.
28
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Conditions May Occur In:
3 Troubleshooting and Testing
Condition Possible Cause
Air leak at turbo
cut-off valve vent.
Rubber seal
damaged or missing.
Temperature of air coming into
dryer is too high — not enough
cooling takes place before dryer
inlet.
NOTE: As of Nov.
2009, the turbo
cut-off valve will have
an O-ring instead of a
lip seal.
Lip seal installed upside-down
on piston. Lip must face UP
(towards dryer).
Valve bore worn excessively. Yes Yes Inspect valve bore for wear. If a new
Piston is broken. Yes Yes Replace the turbo cut-off valve.
Air dryer frozen
(water collecting in
No electrical power to heater
connector.
base of dryer is
freezing).
Low voltage to heater connector. Yes Yes Repair cause of low voltage, such as
Regeneration
Style Air
Dryers
Dedicated
Purge Tank
Air Dryers
Solution
Yes Yes Move dryer farther from compressor.
Add additional compressor discharge
line before air dryer. Add cooling coil or
heat exchanger before air dryer.
NOTE: Inlet air temperature must not
exceed 175°F (80°C).
Yes Yes Install lip seal correctly.
turbo cut-off valve does not seal in a
clean, lubricated bore, replace the air
dryer.
Yes Yes Check for a blown fuse. Repair heater
circuit.
NOTE: There must be power to the
heater connector the entire time the
vehicle’s ignition is ON.
poor electrical ground, bad connections,
corroded wire splices, etc.
Heater assembly not working. Yes Yes Replace heater assembly.
Wrong voltage air dryer used;
i.e., 12-volt air dryer used in a
24-volt system.
Yes Yes Replace with correct voltage air dryer.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
29
3 Troubleshooting and Testing
Conditions May Occur In:
Condition Possible Cause
No air pressure
build-up in system.
Air dryer not plumbed correctly
(connections reversed).
Wrong air line connected to
dryer port 4.
Air governor not working
properly.
Air system leaks, such as
compressor discharge line, air
dryer, reservoirs, brake or
suspension valves, etc.
Air dryer leaks from purge valve. Yes Yes Refer to purge valve conditions listed in
Pressure protection elements
will not open.
Water in tanks; often
following
aftermarket
installation or when
dryer is a
replacement for a
Pressure-controlled check valve
not installed in correct tank or
not installed at all.
Pressure-controlled check valve
properly installed, but one-way
check valve not removed.
competitive brand.
Water, oil, or sludge
Desiccant contaminated with oil. Yes Yes Replace desiccant. Inspect compressor
in air system tanks.
Water in system
tanks.
Dessicant saturated.
Maintenance interval not
followed.
Regeneration
Style Air
Dryers
Dedicated
Purge Tank
Air Dryers
Solution
Yes Yes Ensure compressor discharge line is
plumbed to air dryer port 1, and air
dryer port 21 is connected to vehicle’s
supply tank.
Yes Yes Ensure dryer port 4 line is connected to
the “UNL” port of the air governor.
Yes Yes Inspect governor per manufacturer’s
instructions. Repair or replace as
needed.
Yes Yes Locate leak(s) and repair.
this chart.
Yes Yes Replace the air dryer. The pressure
protection elements are
non-serviceable.
Yes No Install pressure-controlled check valve
in secondary tank.
Yes No Remove one-way check valve so that
only the pressure-controlled check valve
is installed between the secondary tank
and supply tank.
per manufacturer’s instructions.
Yes Yes Replace dessicant cartridge.
Water in system
tanks, everything
Dryer not suitable for
application.
else checks out
okay.
30
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Yes Yes Review the application guidelines. Refer
to TP-9672. For assistance, call the
Meritor OnTrac™ Customer Call Center
at 866-OnTrac1 (668-7221).
3 Troubleshooting and Testing
PSI
20
40
60
80
100
110
120
1002161a
PRIMARY
AIR SUPPLY
(RED)
SECONDARY
AIR SUPPLY
(WHITE)
Tests
Heater Resistance
1. Set volt-ohmmeter to ohms.
2. Disconnect the vehicle harness at the heater.
3. Place leads on the two pins on the heater connector at the air
dryer.
4. Check the resistance. A resistance of 1.0-2.0 ohms should be
seen for a 12-volt heater assembly and 5.0-7.0 ohms should
be seen for a 24-volt heater assembly.
앫 If there is correct resistance on the dryer side and
there is voltage at the harness: The heater is functioning
correctly. Reinstall the components and harness.
앫 If resistance is less than 1.0 ohm for a 12-volt heater
assembly or 5.0 ohms for a 24-volt heater assembly:
Replace the heater.
To avoid damaging components, Meritor WABCO recommends
performing this resistance check with the heater in place.
NOTE: The dryer temperature must be in thermostat closed range
(below 35°F) in order to check heater resistance.
No Soap Bubbles: Connections are sealed properly.
Soap Bubbles Appear: Connections are NOT sealed properly.
To Repair Incorrectly Sealed Connections
1. Drain all reservoirs.
2. Remove leaking connection.
3. Inspect the connectors and ports for damaged threads or
cracks. Replace if necessary.
4. Apply pipe sealant to the connection.
5. Repeat leak test until all connections are sealed.
Air Pressure Checks
NOTE: When checking air pressure during these tests, do not rely
on cab air gauges for accurate readings. Install a calibrated air
gauge, accurate to within one psi (7 kPa), in the secondary air tank
to determine if air pressure is within the required ranges.
Operational Test for System Saver Series Air
Dryers — Regeneration and Purge Style
1. Check compressor loaded and unloaded cycle. Figure 3.2.
Electric Power to Dryer
1. Set the volt-ohmmeter to volts.
2. Disconnect the vehicle harness at the heater.
3. Place leads on each pin of the wiring harness connector.
4. If there is an abnormal voltage reading, inspect the wiring
harness, wires and fuses.
Leak Test
1. Drain air from all system tanks.
2. Close reservoir draincocks.
3. Start the vehicle. Allow air system pressure to build while
engine idles.
4. When the system reaches cut-out pressure there will be a
purge, or strong blast of air, followed by a mild flow which will
last 10-45 seconds.
5. Shut off the engine.
6. Apply a soap solution to each connection that contains
pressurized air. Check the connections to see if soap solution
bubbles.
Figure3.2
Figure 3.2
When the compressor is in the loaded cycle, air pressure will
build to approximately 120-140 psi (827-965 kPa) (cut-out
pressure). When the compressor reaches the unloaded cycle,
the air dryer will purge, initiating regeneration of the air dryer.
2. For regeneration style air dryers, the regeneration cycle, which
lasts from 10-35 seconds, the supply and secondary tanks will
drop approximately 10 psi (69 kPa) in pressure. Check the
secondary air gauge on the vehicle dash panel to verify this
drop.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
31
3 Troubleshooting and Testing
PSI
20
40
60
80
95
110
120
1002162a
PRIMARY
AIR SUPPLY
(RED)
SECONDARY
AIR SUPPLY
(WHITE)
NOTE: On System Saver 1200 Plus MCP air dryers, the
primary and secondary tanks may fill independently due to
pressure protection elements.
NOTE: A 10 psi (69 kPa) drop in pressure in the secondary air
system is normal for Meritor WABCO System Saver Series
regeneration style air dryers.
NOTE: On purge-tank style and System Saver 1200 Plus air
dryers, the regeneration cycle time is dependant on the size of
the tank. There should be no visible pressure drop during
regeneration. If there is a visible pressure drop, perform a
check valve leak test on the system check valves.
3. Step 3 applies to regeneration style air dryers only. If there
is no drop in pressure, one of the following conditions may
apply:
앫 Pressure-controlled check valve not installed, or installed
on wrong air tank.
앫 Pressure-controlled check valve installed to a one-way
check valve, instead of in place of a one-way check valve.
앫 There is another check valve located between the air dryer
and the secondary air tank, usually at the supply tank.
Pressure-Controlled Check Valve Test —
Regeneration Style Only
1. Turn off the engine after the air system reaches cut-out
pressure, approximately 120 psi (827 kPa), and the air
compressor has unloaded.
2. Drain the supply tank down to 80 psi (552 kPa) or lower.
NOTE: A drop from 120 to 95 ± 5 psi (827 to 655 kPa) during
this test is normal for vehicles equipped with the System Saver
Series air dryer and a pressure-controlled check valve.
3. Check the secondary tank air gauge. It should read 95 ± 5 psi
(655 kPa). Figure 3.3.
Figure3.3
앫 Secondary air gauge not plumbed to the secondary air
system. Use a calibrated air gauge in the secondary tank to
check air pressure.
— Make the necessary installation changes or repairs and
repeat the operational test.
— If the secondary pressure drops 25 psi (172 kPa) or
more during the regeneration cycle — and there are no
other air-operated components using air during this
cycle — there are air leaks or other air system
problems, or the pressure-controlled check valve is not
operating correctly.
— Identify and repair all air leaks and air system problems.
— Clean the Regeneration and Outlet Check valves.
— Disconnect the compressor line from the air dryer (Dryer
Port 4). Check the compressor and governor per the
manufacturer’s recommendation.
Figure 3.3
4. If the secondary tank air gauge reading is less than 90 psi
(62 kPa):
앫 Pressure-controlled check valve may be installed
backwards (arrow on valve must point toward host
reservoir). Make necessary corrections and retest.
앫 Check for leaks in the secondary air system. Identify and
repair any leaks.
앫 Pressure-controlled check valve may not be set correctly or
is not operating correctly. Replace the valve.
5. If the secondary tank air gauge reading does not change — or
the reading does not drop below 100 psi (689 kPa), one of the
following conditions may apply:
앫 Pressure-controlled check valve not installed, or installed
on wrong air tank.
앫 Pressure-controlled check valve installed TO a one-way
check valve, rather than IN PLACE OF a one-way check
valve.
32
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
앫 There is another check valve located between the air dryer
and the secondary air tank, usually at the supply tank.
앫 Secondary air gauge not plumbed to the secondary air
system. Use a calibrated air gauge in the secondary tank to
check air pressure.
앫 Make the necessary installation changes or repairs and
repeat the operational test.
3 Troubleshooting and Testing
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
33
4 Appendix I — Glossary
4 Appendix I — Glossary
Definitions
Basic Air System/Air Dryer Terms
Air Compressor A device that pumps air to and builds air pressure in an air system.
Air Dryer A device that cools, filters, and dries the air delivered by an air compressor.
Air Governor A device that controls the operation of the air compressor by constantly monitoring air pressure in the
supply tank of the air system. The air governor initiates the compressor load cycle when “cut-in”
pressure is realized, and initiates the compressor unload cycle when the “cut-out” pressure is reached.
The air governor also controls the air dryer by sending an air signal (at the beginning of the compressor
unload cycle) to the control port of the air dryer, initiating the purge cycle. When this air signal is
removed by the governor (at the beginning of the compressor load cycle), the purge valve closes and the
drying cycle begins.
Compressor Load Cycle The time during which the air compressor is building air pressure in an air system.
Compressor Unload Cycle The time during which the air compressor is idling and is not building air pressure in an air system.
Cut-In Pressure The pressure level in the air system supply tank which triggers the compressor load cycle.
Cut-Out Pressure The pressure level in the air system supply tank which triggers the compressor unload cycle.
Dedicated Purge Tank A separate air tank used exclusively for holding air used in an air drying cycle. This tank eliminates the
need for a regeneration valve. Optimum mounting location for the dedicated purge tank is ABOVE the air
dryer.
Desiccant A granular substance that has a high affinity for water and is used to retain moisture from the air stream
flowing through the air dryer cartridge.
Discharge Line — Unloaded
Compressor
Drying Cycle The time during which the air dryer cools, filters, and removes moisture from the air delivered by the air
Purge The initial blast of air (decompression) from the air dryer purge valve at the beginning of the unload
Purge Cycle The time during which the air dryer is undergoing purge and regeneration. This cycle starts at the
Regeneration The mild backflow of air through the air dryer and out the purge valve that begins immediately after the
An unloader or air discharge line used to dump unused air to atmosphere once system has reached
cut-out pressure.
compressor. The drying cycle begins and ends the same as the compressor load cycle.
cycle of the air compressor.
beginning of the compressor unload cycle and normally ends well before the beginning of the
compressor load cycle.
purge and lasts normally 10 to 25 seconds. This backflow of air from the air system and through the air
dryer removes moisture from the desiccant cartridge and readies the air dryer for the next compressor
load cycle.
34
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
5 Appendix II — Application Info
WARNING
5 Appendix II — Application Info
Hazard Alert Messages
Read and observe all Warning and Caution hazard alert messages in
this publication. They provide information that can help prevent
serious personal injury, damage to components, or both.
To prevent serious eye injury, always wear safe eye protection
when you perform vehicle maintenance or service.
Requirements
NOTE: For complete installation and operating requirements, refer
to TP-9672, Air Dryer Application Guidelines. To obtain this
publication, refer to the Service Notes page on the front inside cover
of this manual.
앫 Compressor discharge line should have a continual downhill run
to the air dryer. There should be no water traps (low points or
kinks) in the line before or after the dryer.
앫 Mount air dryer so that there is no direct splash or spray from a
wheel.
Discharge Line:
앫 Diameter from compressor to air dryer
1/2-inch (12.7 mm) i.d. minimum
앫 Length from compressor to air dryer
Determined by temperature of air at the inlet port of the air dryer.
At normal vehicle operating temperature, the combination of
length or increased diameter must be sufficient to keep
temperature BELOW 175°F (80°C).
Recommendations for discharge lines:
— Compression rating of 21 cfm and under: To minimize the
likelihood of a discharge line blockage during cold climate
operation, it is recommended that for discharge lines exceeding
nine feet (2.75 m) in length, a minimum of three feet (0.91 m) of
1/2-inch (127 mm) thick closed-cell polyethylene pipe insulation
be used at the connection to the air dryer.
— Compression rating over 21 cfm: 10 feet (3.05 m)/20 feet
(6.1 m) — use copper pipe or stainless steel braided teflon
tubing for minimum of first 10 feet (3.05 m).
앫 For maximum operating efficiency, mount dedicated purge tank
ABOVE the air dryer.
앫 Keep air dryer at least 12-inches (305 mm) from any
heat-producing sources like exhaust manifolds or pipes,
transmissions, etc.
앫 Make sure there are no valves or other devices in the
dryer-to-supply-tank line to prohibit or restrict the flow of air
back from the supply tank to the air dryer.
앫 Feed purge valve by a direct line from the air governor.
Operating Environment
Operating Parameter Requirement
Temperature (ambient
operating range)
Electrical Power (for heater
and solenoid/timer power)
Thermostat Range (On/Off
temp)
−40°F to 175°F (−40°C to
80°C)
12 or 24 volts available
45°F, 8 6°F (7°C, 30°C)
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
35
5 Appendix II — Application Info
System Saver Series Installation Criteria
Operating Parameters Requirements
Pressure requirements Maximum pressure 140 psi (965 kPa)
Minimum governor cut-out
pressure
Governor range 15 to 25 psi (103 to 172 kPa) (cut-out — cut-in)
Flow capacity Compressor rating 25 cfm maximum
Compressor on-time Normal running Two minutes maximum
Occasional (three times per
day maximum)
Compressor unloaded time Minimum for purge cycle 20 seconds
Maximum duty cycle Compressor on-time total
running time
Discharge line Temperature at inlet port
determines required length
and diameter.
115 psi (793 kPa)
Seven minutes
30%
To minimize the likelihood of a discharge line blockage during cold
climate operation, it is recommended that for discharge lines
exceeding nine feet (2.75 m) in length, a minimum of three feet
(0.91 m) of 1/2-inch (127 mm) thick closed-cell polyethylene pipe
insulation be used at the connection to the air dryer.
36
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
6 Appendix III — Special Applica tions
PURGE
VA LV E
(EXHAUST)
COMPRESSOR
DISCHARGE
LINE
COMPRESSOR
COMPRESSOR
INTAKE LINE
PRESSURECONTROLLED
CHECK VALVE
SUPPLY
TANK
SYSTEM
RESERVOIRS
ONE-WAY
CHECK
VA LV E
DRYER
INLET
PORT
UNLOADER
LINE
RESERVOIRTO-GOVERNOR
LINE
1800
1200
ECON
VA LV E
CHECK VALVE
(FLOW DIRECTION)
BACKFEED
LINE
SUPPLY
LINE
SIGNAL
LINE
COMPRESSOR
DISCHARGE
LINE
DRYER
OUTLET
PORT
REGENERATION
VA LV E
4003880a
GOVERNOR
CONTROL
(PURGE)
PORT
SYSTEM SAVER SERIES
REGENERATION
STYLE AIR DRYER
UNLOADER
PORT
Description
Holset E-Type Compressor Systems
When a System Saver Series air dryer is used with a Holset E-type
compressor system, an external Econ valve is used. Figure 6.1.
Figure6.1
6 Appendix III — Special Applications
Figure 6.1
On the 1200E Series, an integral Econ valve eliminates the need for
the external Econ valve. Figure 6.2.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
37
6 Appendix III — Special Applications
1002187b
PURGE
VA LV E
(EXHAUST)
COMPRESSOR
DISCHARGE
LINE
COMPRESSOR
CONTROL
(PURGE)
PORT
COMPRESSOR
INTAKE LINE
PRESSURECONTROLLED
CHECK VALVE
SUPPLY
TANK
SYSTEM
RESERVOIRS
ONE-WAY
CHECK
VA LV E
SYSTEM SAVER 1200E AIR DRYER
WITH REGENERATION AND TURBO
CUT-OFF — ECON VALVE NOT REQUIRED
DRYER
INLET
PORT
UNLOADER
LINE
RESERVOIRTO-GOVERNOR
LINE
1200E
DRYER
OUTLET
PORT
REGENERATION
VA LV E
GOVERNOR
UNLOADER
PORT
Figure6.2
Figure 6.2
If you are currently using a System Saver Series air dryer WITHOUT
an Econ valve, and your application requires one, Meritor WABCO
recommends installing the System Saver 1200E.
ECON Valve
Meritor WABCO recommends the ECON valve be mounted in the air
system away from the dryer. This helps prevent dryer freeze-up.
Refer to the vehicle manufacturer’s manual for installation
instructions.
To replace an ECON valve that is mounted directly to the air dryer,
follow these instructions.
1. Unscrew and remove all of the lines from the Econ valve at the
air dryer inlet port. Figure 6.3.
38
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
6 Appendix III — Special Applications
1002186b
ECON
VA LV E
PRESSURE
RELIEF VALVE
ASSEMBLY
PORT 1
METAL
WASHER
COMPRESSION
FEMALE
NUT
COMPRESSION
FEMALE
NUT
ECON
VA LV E
METAL
WASHER
O-RING
TUBE
BANJO
FITTING
4003881a
ECON
VA LV E
WASHER
TUBE
BANJO
FITTING
4003882a
Figure6.3
Figure6.4
Figure 6.4
Figure6.5
Figure 6.3
2. Unscrew and remove the Econ valve from the air dryer inlet
port 1. Save fitting for reinstallation.
3. Install the replacement Econ valve.
앫 Apply a good quality teflon paste pipe sealant, like Loctite
PST 567, on male threads of the replacement Econ valve.
4. Reconnect the lines to the Econ valve at air dryer inlet port
(Port 1).
ECON Valve Replacement on System Saver 1200E
Air Dryers
To replace the Econ valve assembly on Meritor WABCO System
Saver 1200E air dryers, follow these instructions.
1. Remove the Econ valve assembly.
A. Using a flare wrench, loosen the compression nuts on
each end of the U-shaped tube. Figure 6.4 and
Figure 6.5.
Figure 6.5
B. Loosen and remove the restricted-flow nut on the air
dryer.
C. Remove the metal washer.
D. Using a wrench, loosen and remove the Econ valve from
the banjo fitting.
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
39
6 Appendix III — Special Applications
E. Remove the banjo fitting and metal washer.
F. Clean the valve surface area thoroughly before
replacement.
2. Install the replacement Econ valve assembly.
A. Install the metal washer on the restricted-flow nut.
B. Install the restricted-flow nut on the air dryer.
C. Position the metal washer and banjo fitting on the Econ
valve port.
D. Loosely fit the U-shaped tube into the banjo fitting and
restricted-flow nut. Make sure the tube is fully seated.
E. Install and hand-tighten the compression nuts on each
end of the U-shaped tube.
F. Lubricate and install the O-ring on the Econ valve.
G. Install the Econ valve into the banjo fitting.
H. Torque the Econ valve and all nuts to specifications
following the torque instructions in the kit.
Alcohol Evaporator
Check the vehicle’s air system for an alcohol evaporator.
3. If a bypass line is connected to the evaporator, check to see if a
check valve is installed in the bypass line. If check valve is
installed:
앫 Remove the check valve from the bypass line,
앫 Remove the bypass line and
앫 Replace the bypass line with 1/4-inch (6.35 mm) nylon line.
NOTE: Typically, an alcohol evaporator will be installed in the line
between the air dryer and the supply (wet) tank. Common
installations are on the truck’s firewall, on a frame rail and behind
the cab. However, an alcohol evaporator can also be found at other
locations.
1. Check the vehicle’s air system to determine if an alcohol
evaporator is installed.
2. If an alcohol evaporator is installed in the air system, check for
a bypass line connected to the evaporator. Figure 6.6.
Figure6.6
LINE TO
LINE FROM
AIR DRYER
ALCOHOL
EVAPORATOR
SUPPLY TANK
1002188a
Figure 6.6
40
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
6 Appendix III — Special Applications
PURGE
VA LV E
(EXHAUST)
COMPRESSOR
DISCHARGE
LINE
COMPRESSOR
COMPRESSOR
INTAKE LINE
PRESSURECONTROLLED
CHECK VALVE
*
SUPPLY
TANK
(WET)
SYSTEM
RESERVOIR
INTERNAL
CHECK
VA LV E
DRYER
INLET
PORT
UNLOADER
LINE
RESERVOIRTO-GOVERNOR
LINE
1800
1200
SYSTEM
RESERVOIR
CHECK
VA LV E
SUPPLY
LINE
DRYER
OUTLET
PORT
REGENERATION
VA LV E
GOVERNOR
*
ALTERNATE PCCV LOCATION
WITH COMBO RESERVOIR
CONTROL
(PURGE) PORT
SYSTEM SAVER SERIES
REGENERATION
STYLE AIR DRYER
UNLOADER
PORT
4003883a
Combo Tank Installation for Regeneration-Style Air Dryers
Figure6.7
Figure 6.7
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
41
6 Appendix III — Special Applications
PURGE
VA LV E
(EXHAUST)
COMPRESSOR
DISCHARGE
LINE
COMPRESSOR
COMPRESSOR
INTAKE LINE
PRESSURECONTROLLED
CHECK VALVE
*
SUPPLY
TANK
(WET)
SYSTEM
RESERVOIR
INTERNAL
CHECK
VA LV E
DRYER
INLET
PORT
UNLOADER
LINE
1800
1200
SYSTEM
RESERVOIR
SUPPLY
LINE
DRYER
OUTLET
PORT
*
ALTERNATE PCCV LOCATION
WITH COMBO RESERVOIR
GOVERNOR
UNLOADER
PORT
CONTROL
(PURGE) PORT
SYSTEM SAVER SERIES
REGENERATION
STYLE AIR DRYER
RESERVOIRTO-GOVERNOR
LINE
REGENERATION
VA LV E
4003884a
Combo Tank Installation for Regeneration-Style Air Dryers
Figure6.8
Figure 6.8
42
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
6 Appendix III — Special Applications
O-RING
HEATER ASSEMBLY
DESICCANT CARTRIDGE
PRESSURE RELIEF VALVE
PURGE VALVE ASSEMBLY
OUTLET CHECK
VALVE ASSEMBLY
TURBO CUT-OFF
VALVE ASSEMBLY
1800
1200
Spring not used with U Series dryers.
4003885a
Meritor WABCO System Saver Series Single Cartridge Air Dryer Component Replacement
Guide — Dedicated Purge
Figure6.9
Figure 6.9
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
43
6 Appendix III — Special Applications
BYPASS VALVE
ASSEMBLY
Bypass valve is used on
dryers with date codes
earlier than 0894.
1002189a
O-Ring
Do not grease
diaphragm.
1200 Series air dryers do
not use bypass valve.
HEATER ASSEMBLY
• Disconnect plug.
• Remove old assembly.
• Install replacement element and
thermostat.
— Install retainer and screw to secure.
• Install replacement O-ring and receptacle.
— Fasten in place with screws.
Refer to Section 3 for more
detailed instructions.
DESICCANT CARTRIDGE
• Remove old cartridge.
• Lube and install O-ring.
• Install replacement cartridge.
T
PRESSURE RELIEF VALVE
• Unscrew and remove
old valve.
• Screw replacement
valve into dryer or
Street-Tee fitting.
• Do not exceed
recommended torque.
Refer to Pressure Relief
Valve in Section 3.
REGENERATION
VALVE ASSEMBLY —
REGENERATION STYLE
DRYERS ONLY
• Remove old assembly and
diaphragm.
• Clean diaphragm lip groove.
• Install replacement
diaphragm and assembly.
PURGE VALVE ASSEMBLY
• Remove old assembly.
• Clean valve bore.
• Grease valve bore.
• Install replacement assembly.
*
E Series dryers use a different style turbo
cut-off valve (Refer to Parts Book PB-96134).
**
Spring not used with U Series dryers.
NOTE: If shims are included in the
replacement kit, install one above
and one below the spring.
OUTLET CHECK
VALVE ASSEMBLY
• Remove old
assembly.
• Clean valve bore.
• Install replacement
O-ring in bore.
Then, grease O-ring
and bore.
TURBO CUT-OFF
VALVE ASSEMBLY
*
• Remove snap ring.
• Use needle nose pliers
to remove the piston.
• Clean bore (if bore is
badly damaged,
replace the air dryer).
• Install replacement
assembly.
* *
1800
1200
SHIMS
(IF REQUIRED)
Meritor WABCO System Saver Series Single Cartridge Air Dryer Component Replacement
Guide
NOTE: Whenever an assembly is replaced due to seal damage from oil contamination, it is recommended that you find and correct the source
of the oil contamination and replace the desiccant cartridge.
Figure6.10
Figure 6.10
44
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
7 Appendix IV — Exploded View of System Saver 1200 Plus Series Air Dryer
4007692a
PRESSURE
RELIEF
VA LV E
DESICCANT
CARTRIDGE
SYSTEM SAVER 1200 PLUS SERIES AIR DRYER
OUTLET
CHECK
VA LV E
ASSEMBLY
GOVERNOR
O-RING
PURGE VALVE
ASSEMBLY
TURBO
CUT-OFF
VA LV E
ASSEMBLY
HEATER
ASSEMBLY
Figure7.1
7 Appendix IV — Exploded View of System Saver 1200 Plus Series Air Dryer
Figure 7.1
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
45
8 Appendix V — Temporary Air Dryer Bypass
WARNING
CAUTION
CAUTION
8 Appendix V — Temporary Air Drye r Bypass
Hazard Alert Messages
Read and observe all Warning and Caution hazard alert messages in
this publication. They provide information that can help prevent
serious personal injury, damage to components, or both.
To prevent serious eye injury, always wear eye protection
when you perform vehicle maintenance or service.
Park the vehicle on a level surface. Block the wheels to
prevent the vehicle from moving. Support the vehicle with
safety stands. Do not work under a vehicle supported only by
jacks. Jacks can slip and fall over. Serious personal injury and
damage to components can result.
Open drain valves on all reservoirs to remove all pressurized
air from the air system before you disconnect any component.
Pressurized air can cause serious personal injury.
Bypass Procedure
If the air dryer were to malfunction in a way that the air compressor
cannot build up pressure within the system and the air dryer cannot
be immediately repaired, a temporary bypass of the air dryer may be
required. The bypass is a short term remedy only until the vehicle
can make it to a repair facility and either have the air dryer repaired
or replaced. Long term use of the vehicle with the air dryer
bypassed could result in excessive moisture build up in the air
system.
1. Wear safe eye protection.
Figure8.1
T-FITTING
4009783a
Figure 8.1
7. Using the original fittings, reinstall the discharge line in one of
the branches of the T-fitting.
8. Using the original fittings, install the air supply line into the
remaining T-fitting port.
9. Charge the system to cut-out pressure and use a soap solution
to test the T-fitting for air leaks. The vehicle may then be
returned to temporary service.
This is a temporary bypass of the air dryer, and full repair of
the unit must be carried out at the earliest opportunity. Long
term use of the vehicle with the air dryer bypassed could
result in excessive moisture build up in the air system.
2. Park the vehicle on a level surface. Block the wheels to prevent
the vehicle from moving.
3. Drain the entire air system. Open all of the drain valves on all of
the reservoirs.
4. Ensure that all residual pressure has been released and the air
dryer has been drained to 0 psi. Then, remove the air supply
line from the compressor to the inlet port.
5. Remove the air line from the dryer discharge port.
6. Install a T-fitting into the discharge port. Figure 8.1.
46
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
Drain Air Reservoirs Daily Until Repairs are
Completed
Long term use of the vehicle with the air dryer bypassed could
result in excessive moisture build up in the air system.
Once the air dryer is removed, contaminants will enter the air
system. Therefore, you will need to manually drain the reservoirs
daily until the repairs are completed.
1. At end of each working day, park the vehicle and slowly drain
pressure through the drain valves. Leave the valves open to the
atmosphere for several hours if possible.
2. When repairs are completed, be sure to check that all
reservoirs (including the air dryer) are emptied of all
contaminants.
9 Appendix VI — Exploded View of System Saver 1200 Plus Series with Multi Circuit
Protection
9 Appendix VI — Exploded View of System Saver 1200 Plus Series with Multi Circuit Protection
Figure9.1
SYSTEM SAVER 1200 PLUS SERIES AIR DRYER
WITH MULTI CIRCUIT PROTECTION
DESICCANT
CARTRIDGE
PURGE VALVE
Figure 9.1
DRAIN
VA LV E
ASSEMBLY
PRESSURE
RELIEF VALVE
TURBO
CUT-OFF
VA LV E
ASSEMBLY
HEATER ASSEMBLY
GOVERNOR
OUTLET CHECK
VALVE ASSEMBLY
O-RING
4011774a
Meritor WABCO Maintenance Manual 34 (Revised 03-16)
47
Meritor WABCO Vehicle Control Systems
2135 West Maple Road Printed in USA
Troy, MI 48084-7121
866-OnTrac1 (668-7221) Copyright 2016 Revised 03-16
meritorwabco.com Meritor, Inc. Maintenance Manual 34 (16579)
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