SYSTEM SAVER HP AIR DRYER - WABCO Customer Centre

Component Removal and InstallationEN4Component Removal and InstallationWARNINGTo prevent serious eye injury, always wear safe eye protection when you perform vehiclemaintenance or service.WARNINGPark the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support thevehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip andfall over. Serious personal injury and damage to components can result.WARNINGRemove all pressure from the air system before you disconnect any component, including thedesiccant cartridge. Pressurized air can cause serious personal injury.The pressure protection elements are not serviceable on the System Saver HP. The entiredryer needs to be replaced if these parts are not operating effectively.ii4.1Component Replacement4.1.1RequirementsRefer to Table B for component replacement requirements. If necessary, you may also refer to Table E forSystem Saver Series air dryer troubleshooting. Before replacing any air dryer component, verify that the aircompressor 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 beforeservicing the air dryer, check for water and/or oil that may have accumulated in the tanks. Water and/or oilin the air tanks could indicate a problem with the dryer or compressor.14

Component Removal and InstallationTable B: Replacement RequirementsComponentWhen to ReplaceWhyCartridgeEvery two to three years for standarddessicant.Every one to two years for coalescing.Preventative maintenance.When compressor is replaced.Contaminated cartridge.Water in supply tank.Saturated or contaminated cartridge,high duty cycle (wrong application ofair dryer).HeaterAssemblyWater collecting in air dryer is freezing —electrical power to dryer is OK.Heater assembly not working(internal short or open circuit).Outlet CheckValveAir continues to flow from purge valve afterpurge cycle, but stops flowing when thecompressor load cycle begins.Valve is stuck in the open position, ornot functioning correctly.No pressure build-up in system, everythingelse is OK.Valve is stuck in closed position.No purge cycle when compressor unloads— normal pressure at dryer control port 4(governor port).Valve is stuck in the closed position,or not functioning correctly.Air flows from purge valve duringcompressor’s load cycle — no pressure atdryer control port.Valve is stuck in the open position, ornot functioning correctly.Purge ValveTurbo Cut-OffValveENAir compressor stuck pumping, TCU remains Signal line loss.open. System will build pressure until safetyvalve opens in system.Air flows from purge valve duringcompressor unload cycle after purge cycle,and flow is noticeably stronger at highengine RPM, especially under load.Turbo cut-off valve leaking.No pressure build-up in system — highcompressor discharge line pressure.Valve stuck in closed position.15

Component Removal and InstallationEN4.2Component Removal and Installation ProceduresWARNINGTo prevent serious eye injury, always wear safe eye protection when you perform vehiclemaintenance or service.WARNINGPark the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support thevehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip andfall over. Serious personal injury and damage to components can result.WARNINGRemove all pressure from the air system before you disconnect any component, including thedesiccant cartridge. Pressurized air can cause serious personal injury.The pressure protection elements are not serviceable on the System Saver HP. The entire airdryer needs to be replaced if these parts are not operating effectively.iiWhen replacing air dryer components, use only WABCO replacement parts.iiThe exploded view of the air dryer in Section 3 shows the location of the various air dryer components.4.2.1Desiccant CartridgeIMPORTANT NOTE: Refer to Table C for correct desiccant cartridge part numbers to use withthe air dryer.iiTable C: Replacement Cartridges16Air Dryer Part NumberReplacement Cartridge Part Number432 480 001 0432 901 238 2432 480 101 0432 901 238 2432 480 141 0432 901 248 2432 480 201 0432 901 238 2432 480 301 0432 901 238 2432 480 341 0432 901 248 2

Component Removal and Installation1. Verify the replacement kit contains one cartridge and one O-ring. Figure 12.ENFig. 121002234a2. Loosen and remove the old cartridge. Use strap a wrench if necessary.3. Remove and discard O-ring from dryer base.4. Inspect and clean seal seat. Figure 13. Repair any minor damage.If the seal seats are damaged so badly that a tight seal cannot be maintained, replace the airdryer.iiFig. 13O-RINGSEAL SEATSEAL1002164a5. Lubricate and install the new O-ring on the stem.6. Lubricate cartridge seal.7. Thread the replacement cartridge onto the base until the seal touches the base. Then, tighten thecartridge ONE additional turn. DO NOT OVERTIGHTEN. Figure 13. If the cartridge will not fully spin onthe dryer, the wrong cartridge is being use. Refer to the IMPORTANT NOTE and table.17

Component Removal and InstallationEN4.2.2Outlet Check Valve Assembly1. Review Figure 14 to ensure you have all of the parts required to replace the outlet check valve. Use thegrease included with the replacement kit to lubricate the O-ring seal.Fig. a2. 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 15.Fig. 15O-RINGVALVEBODYSPRINGWASHERSNAP RING1002166a5. Apply a thin layer of grease from the kit 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.8. Install the new washer and the new snap ring to hold the components in place.18

Component Removal and Installation4.2.3Heater AssemblyEN1. Review Figure 16 to ensure you have all of the parts required to replace the heater assembly.Fig. . Disconnect the plug.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.7. Install the new retainer and screw to hold the element and the thermostat in place.8. Install the receptacle and fasten it in place with the screws. Figure 17.Fig. 9

Component Removal and InstallationEN4.2.4Turbo Cut-Off Valve AssemblyUse the grease included with the replacement kit to lubricate the O-rings and seals.ii1. Remove the snap ring. Figure 18.Fig. 18O-RINGPISTONO-RINGSLEEVECOVERSNAPRING4013287a2. 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.4.2.5GovernorFunction — The governor controls the cut-in and cut-out pressure of the compressor through signal linesfrom the system reservoir as well as the compressor head controlling onload and offload.Use only the WABCO governor specified for use with the System Saver HP air dryer.ii20

Component Removal and Installation1. Using a 1-3/16″ wrench, remove the governor from the air dryer. Figure 19.ENFig. 19GOVERNOR4013360a2. Install the new governor into the air dryer. Use a 1-3/16″ wrench to tighten it to no more than 8.85 ft-lb(12 Nm).4.2.6Purge Valve Assembly1. Use a 1-11/16″ wrench to remove the purge valve assembly from the air dryer. Figure 20.Fig. 20PURGE VALVEASSEMBLY4013568a2. Clean and inspect the valve bore. If the bore is damaged so that a tight seal cannot be maintained,replace the air dryer.3. Install the purge valve assembly in the air dryer. Use a 1-11/16″ wrench to tighten it to no more than11 ft-lb (15 Nm).4.2.7Air Dryer AssemblyThis procedure is for removing and replacing a unit. For instructions on an initial installation,refer to TP92116, Installing the WABCO System Saver Air Dryer. To obtain this publication, goto wabco-na.com.ii1. Drain all pressure from the air system. Disconnect the air lines from port 1, port 2.2 and port 4.Use markers to label the lines for correct installation.21

Component Removal and Installation2. Disconnect the heater electrical plug from the heater receptacle.EN3. Remove the three mounting bolts. Remove the air dryer from its mounting location. Figure 21.Fig. 214013563a4. Attach the new unit to the frame or mounting bracket with new mounting bolts and washers. Tighten thebolts to 22-30 ft-lb (30-40 Nm). Figure 22.Fig. 224013564a5. Connect the heater electrical plug to the heater receptacle.6. Reconnect all system air lines.7. Test the installation for correct operation. Refer to the procedure in this section.22

Troubleshooting and Testing5Troubleshooting and TestingENWARNINGTo prevent serious eye injury, always wear safe eye protection when you perform vehiclemaintenance or service.WARNINGPark the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support thevehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip andfall over. Serious personal injury and damage to components can result.WARNINGRemove all pressure from the air system before you disconnect any component, including thedesiccant cartridge. Pressurized air can cause serious personal injury.5.1MaintenanceTo keep the air dryer operating efficiently, WABCO recommends the following routine maintenance.Table D: Maintenance ScheduleActionIntervalEnsure the dryer purges when compressorunloads.WeeklyCheck for moisture in the system by opening thedrain cock on vehicle system reservoirs slowly.Weekly, or as recommended by themanufacturer, whichever is most frequent.Replace the standard desiccant cartridge.Every two to three years, or more oftendepending on usage, vocation, and condition ofcompressor.Whenever compressor is rebuilt.Replace the coalescing cartridge.Every one to two years.23

Troubleshooting and TestingEN5.1.1Maintenance TipsWith correct maintenance, the WABCO air dryer will provide years of reliable service, even under adverseoperating conditions. To provide additional protection against the harmful effects of extreme heat or cold,here are a few helpful tips.Extreme HeatMake sure the compressor discharge line is long enough to keep the air dryer inlet air below 175 F (80 C).Figure 23. Refer to Section 7.Fig. 231002159aExtreme ColdMake sure the air dryer heater is in good working order by running a heater resistance test. Refer to theprocedure in this section.Check the line from the compressor to port 4 of the dryer for oil and/or water. Keep this line clean to helpprevent freezing.WABCO air dryer components are installed in the air dryer at the factory and are designed to last for the lifeof the dryer. Under some operating conditions, however, a replacement may be required. Refer to Section 4for replacement guide instructions.5.2TroubleshootingConditions you may experience, and suggested solutions, appear in Table E.Refer to the exploded view of the air dryer in Figure 3 for the location of dryer components.ii24

Troubleshooting and TestingTable E: System Saver HP Series Air Dryer TroubleshootingConditionPossible CauseDryer leaks from purge valve Purge valve frozen openduring compressor loaded(cold weather operation).cycle. The leak may causeexcessive compressor cyclingor prevent the system frombuilding air pressure.Debris under purge valveseat, such as particles fromfittings or air inlet line.ENSolutionCheck heater. Repair/replace if necessary.Make sure governor to dryer port 4 line isfree of water/oil.Remove and inspect purge valve andclean water/oil from top of piston.Remove purge valve cartridge and inspectfor contamination. Remove if possible, orreplace purge valve cartridge.Remove desiccant cartridge and cleansump area.Turbo cut-off valve iscracked or O-rings areleaking.Remove turbo cut-off valve. Clean dryerbore and check for damage. Replace turbocut-off valve if damaged component isfound. Lubricate O-rings .Leaks in governor signalline between port 4 andcompressor.Repair signal line or fittings as necessary.Make sure downward slope of signal linefrom compressor to dryer.Regeneration cycle too long(more than 30 seconds),accompanied by loss ofpressure in the supply tank.Outlet check valve notseating.Inspect and replace outlet check valve asneeded.Regeneration cycle too short(less than 10 seconds).High air system demandsIncrease air system capacity or reduce airduring compressor unloaded demands.cycle.No regeneration cycle. Noairflow from purge valveafter initial purge blast (dryerdecompression).Air governor not workingcorrectly.Verify that dryer governor is operating atcorrect pressures and that signal changeslevels in one second or less. Replace ifnecessary.Air dryer connectionsreversed at dryer.Verify correct dryer installation per systemdiagram.Blocked/contaminated,internal dryer orificeReplace dryer.Air dryer does not purge when Purge valve stuck closed.compressor unloads (no blast Air governor not workingof air from purge valve).correctly.Cut-out pressure neverachieved by air compressor.Replace purge valve.Inspect air governor. Repair/replace perinstructions.Check for air leaks in system and repairas needed. If no leaks in system, checkcompressor output. Repair/replace permanufacturer’s instructions.25

Troubleshooting and TestingEN26ConditionPossible CauseSolutionAir dryer purges too often,perhaps as frequentlyas every 15 seconds,accompanied by excessivecycling of the compressor.Leak in line betweencompressor and dryer port4.Repair air line.Line between the outlet ofthe dryer and the wet tankhas a check valve installed.Line between dryer and wet tank must beunobstructed.Leaks in the air system.Repair leaks.Excessive air systemdemands.Increase air system capacity or reduce airdemand.Outlet check valve notseating.Inspect and replace outlet check valve asneeded.Leaking air compressorunloader(s).Inspect compressor. Repair/replace permanufacturer’s instructions.On air dryers equipped withturbo cut-off valves, the airflows out of purge valve entiretime compressor is unloaded.NOTE: On air dryers notequipped with turbo cutoff valves, the compressorunloads through the dryer, soa steady flow of air is normal.Turbo cut-off valve notsealing.Replace turbo cut-off valve.Outlet check valve notseating.Replace outlet check valve.Rapid “spitting” of air frompurge valve in small amounts.Frequency varies with enginespeed.NOTE: With non-TCV styleair dryers, the compressorunloads through the dryer, soa steady flow of air is normal.Compressor not completelyunloading when cut-outpressure is reached."Non-TCV" means a dryerwith no turbo cut-off valvefunction.Inspect compressor. Repair/replace permanufacturer’s instructions.Make sure there are no leaks in theunloader signal line between thecompressor and port 4 of the dryer.Air dryer frozen (watercollecting in base of dryer isfreezing).No electrical power to heater Check for a blown fuse. Repair heaterconnector.circuit.NOTE: There must be power to the heaterconnector the entire time the vehicle’signition is ON.Low voltage to heaterconnector.Repair cause of low voltage, such aspoor electrical ground, bad connections,corroded wire splices, etc.Heater assembly notworking.Replace heater assembly.Wrong voltage air dryerused; i.e., 12-volt air dryerused in a 24-volt system.Replace with correct voltage air dryer.

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Twin air dryer, use MM35, WABCO System Saver Twin Air Dryer. To download these publications, go to wabco-na.com. 3.2 Air Dryer Identification The System Saver HP air dryer has the governor integrated into the body of the air dryer and also has an integrated purge tank. Figure 1. Fig. 1 4013285a PURGE T