Bendix Commercial Vehicle Systems AD-9 AND AD-9 IPC AIR DRYERS 4/11 User Manual

Bendix® AD-9® and AD-9® IPC (Integrated PuraGuard® Coalescing) Air Dryers

EXTENDED

PURGE

IPC AIR DRYER LABEL

OUTER

SHELL

END COVER

STANDARD

SD-08-2412

SUPPLY

CONTROL

PORT

WIRING HARNESS

DELIVERY PORT

FIGURE 1 - BENDIX

AD-9® AND AD-9® IPC AIR DRYER MODELS

CONNECTION

CHECK

VALVE

ASSEMBLY

END COVER

DESCRIPTION

The function of the Bendix® AD-9® and AD-9® IPC Integrated PuraGuard® Coalescing air dryers is to collect and remove air system contaminants in solid, liquid, and vapor form before they enter the brake system. They provide clean, dry air to the components of the brake system which increases the life of the system and reduces maintenance costs. Daily manual draining of the reservoirs is eliminated.

PORT

PURGE VALVE

SAFETY VALVE

The Bendix AD-9 and AD-9 IPC Integrated PuraGuard Coalescing air dryers consists of a desiccant cartridge and a die cast aluminum end cover secured to a cylindrical steel outer shell with eight cap screws and nuts. The end cover contains a check valve assembly, a safety valve, three threaded air connections, and the purge valve housing assembly. The removable purge valve housing assembly incorporates a purge valve mechanism and a turbocharger cut-off feature that is designed to prevent loss

DESICCANT CARTRIDGE



CHECK

VALVE



ORIFICE



GOVERNOR



COMPRESSOR



RESERVOIR

ENGINE

TURBO



CONTROL

PORT



SUPPLY

PORT



DESICCANT

BED

OIL

SEPARATOR



PURGE

VALVE



EXHAUST







HEATER

ELEMENT



SUMP



DELIVERY

PURGE

VOLUME

CHECK

VALVE

ASSEMBLY

PORT

FIGURE 2 - BENDIX

AD-9® AND AD-9® IPC AIR DRYER CHARGE CYCLE

of engine “turbo” boost pressure during the purge cycle of the Bendix® AD-9® and AD-9® IPC air dryers. For ease of serviceability , the desiccant cartridge and discharge check valve assembly are screw-in type. The purge valve housing assembly – which includes the heater and thermostat assembly – and the discharge check valve assembly are serviceable from the exterior of the air dryer, while servicing the screw-in desiccant cartridge requires removal of the air dryer assembly from the vehicle.

The AD-9 IPC air dryer appears identical to the standard AD-9 air dryer, but contains a coalescing media at the inlet of the desiccant bed. This coalescing media provides a higher level of oil removal over the standard AD-9 air dryer. The AD-9 IPC air dryer has all the same functions of the standard AD-9 air dryer, and is used where oil is contaminating downstream components. The Bendix AD-9 IPC air dryer can be identiﬁ ed by the IPC label (shown in Figure 1), located on the air dryer housing.

The Bendix AD-9 and AD-9 IPC air dryers have three female pipe thread air connections and each is identiﬁ ed as follows:

Port l.D. Function/Connection

CON 4................Control Port

(purge valve control and turbo cut-off)

SUP 11 .............Supply Port (air in)

DEL 2 ...............Delivery Port (air out)

OPERATION OF THE BENDIX AD-9 AIR DRYER

The AD-9 and AD-9 IPC air dryers alternate between two operational modes, or “cycles”, during operation: the charge cycle and the purge cycle. The following description of operation is separated into these “cycles” of operation.

CHARGE CYCLE (Refer to Figure 2)

When the compressor is loaded (compressing air) compressed air – along with oil, oil vapor, water and water vapor – ﬂ ows through the compressor discharge line to the supply port of the air dryer end cover. As air travels through the end cover assembly, its direction of flow

DESICCANT

CARTRIDGE



CHECK

VALVE



ORIFICE



GOVERNOR



COMPRESSOR



RESERVOIR



ENGINE

TURBO

CONTROL

PORT



SUPPLY

TURBO

CUT-OFF

PISTON

DESICCANT

BED

OIL

SEPARATOR



PORT

PURGE

VALVE



EXHAUST







HEATER

ELEMENT



SUMP



PURGE

VOLUME



CHECK

VALVE

ASSEMBLY

DELIVERY

PORT

FIGURE 3 - BENDIX®AD-9® AND AD-9® IPC AIR DRYER PURGE CYCLE

changes several times, reducing the temperature, causing contaminants to condense and drop to the bottom, or sump,

The air dryer will remain in the charge cycle until air brake system pressure builds to the governor cut-out setting.

of the air dryer end cover.

PURGE CYCLE (Refer to Figure 3)

After exiting the end cover, the air ﬂ ows into the desiccant cartridge. Once in the desiccant cartridge, air ﬁ rst ﬂ ows through an oil separator which removes water in liquid form as well as oil and solid contaminants.

Air exits the oil separator and enters the desiccant drying bed. Air ﬂ owing through the column of desiccant becomes progressively drier as water vapor adheres to the desiccant material in a process known as “adsorption”. The desiccant cartridge using the adsorption process typically removes 95% of the water vapor from the pressurized air.

The majority of dry air exits the desiccant cartridge through its integral single check valve to ﬁ ll the purge volume between the desiccant cartridge and outer shell. Some air will also exit the desiccant cartridge through the purge oriﬁ ce adjacent to the check valve.

Dry air ﬂ ows out of the purge volume through the single check valve assembly and out the delivery port to the ﬁ rst (supply) reservoir of the air system.

When air brake system pressure reaches the cut-out setting of the governor, the compressor unloads (air compression stopped), and the purge cycle of the air dryer begins. When the governor unloads the compressor, it pressurizes the compressor unloader mechanism and line connecting the governor unloader port to the air dryer end cover control port. The purge piston moves in response to air pressure, causing the purge valve to open to atmosphere and (partially) closing off the supply of air from the compressor . (This will be further discussed in the section covering the turbo cut-off feature.) Contaminants in the end cover sump are expelled immediately when the purge valve opens. Also, air – which was ﬂ owing through the desiccant cartridge – changes direction and begins to ﬂ ow toward the open purge valve. Oil and solid contaminants collected by the oil separator are removed by air ﬂ owing from the desiccant drying bed to the open purge valve.

UPPER

BRACKET

STRAP

UPPER

BRACKET



PURGE

VALVE



DISCHARGE

LINE

CHECK

VALVE

ASSEMBLY



SUPPLY

PORT

TURBO

CUT-OFF

PISTON

FIGURE 4 - BENDIX® AD-9® AND AD-9® IPC AIR DRYER TURBO CUT-OFF



EXHAUST



The initial purge and desiccant cartridge decompression lasts only a few seconds and is evidenced by an audible burst of air at the Bendix® AD-9® or AD-9® IPC air dryer exhaust.

The actual reactivation of the desiccant drying bed begins as dry air ﬂ ows from the purge volume through the desiccant cartridge purge oriﬁ ce and into the desiccant drying bed. Pressurized air from the purge volume expands after passing through the purge oriﬁ ce; its pressure is lowered and its volume increased. The ﬂ ow of dry air through the drying bed reactivates the desiccant material by removing the water vapor adhering to it. Generally 15–30 seconds are required for the entire purge volume of a standard Bendix AD-9 or AD-9 IPC air dryer to ﬂ ow through the desiccant drying bed.

The end cover single check valve assembly prevents air pressure in the brake system from returning to the air dryer during the purge cycle. After the 30 second purge cycle is complete, the air dryer is ready for the next charge cycle to begin.

The purge valve will remain open after the purge cycle is complete, and will not close until air brake system pressure is reduced and the governor signals the compressor to charge.

TURBO CUT-OFF FEATURE (Refer to Figure 4)

The primary function of the turbo cut-off valve is to prevent loss of engine turbocharger air pressure through the Bendix AD-9 and AD-9 IPC air dryers in systems where the compressor intake is connected to the engine turbocharger. The turbo cut-off valve also reduces the “pufﬁ ng” of air out

DESICCANT CARTRIDGE

DESICCANT

BED

OIL

SEPARATOR

CONTROL

PORT

SUPPLY

PORT

TURBO

CUT-OFF

PISTON

FIGURE 5 - BENDIX® AD-9® AND AD-9® IPC AIR DRYER CROSS SECTION

PURGE VALVE

HOUSING

ASSEMBLY

PURGE

VALVE

HOUSING

LOWER

BRACKET

CHECK

VALVE

ASSEMBLY

DISCHARGE

PORT

the open exhaust when a naturally aspirated, single cylinder compressor equipped with an inlet check valve is in use.

At the onset of the purge cycle, the downward travel of the purge piston is stopped when the turbo cut-off valve (tapered portion of purge piston) contacts its mating metal seat in the purge valve housing. With the turbo cut-off valve seated (closed position), air in the discharge line and air dryer inlet port is restricted from entering the air dryer. While the turbo cut-off effectively prevents loss of turbocharger boost pressure to the engine, some “seepage” of air may be detected under certain conditions of compressor engine and turbocharger operation. Even so, there will always be low pressure trapped in the discharge line.

PREVENTIVE MAINTENANCE

Important: Review the warranty policy before performing

any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period. Note: It is acceptable for the purge valve to be maintained as necessary, (i.e., the installation of a purge valve maintenance kit), without voiding the warranty.

Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary. Experience is a valuable guide in determining the best maintenance interval for any one particular operation.

Every 900 operating hours or 25,000 miles or every three (3) months:

1. Check for moisture in the air brake system by opening reservoirs, drain cocks, or valves and checking for presence of water. If moisture is present, the desiccant may require replacement; however, the following conditions can also cause water accumulation and should be considered before replacing the desiccant:

An outside air source has been used to charge the

system. This air did not pass through the drying bed.

B. Air usage is exceptionally high and not normal for

a highway vehicle. This may be due to accessory air demands or some unusual air requirement that does not allow the compressor to load and unload (compressing and non-compressing cycle) in a normal fashion. Check for high air system leakage. If the vehicle vocation has changed it may be necessary to upgrade the compressor size. Refer to Appendix A, Table A and the column titled Vehicle Vocation.

C. The air dryer has been installed in a system that

has been previously used without an air dryer. This type of system will be saturated with moisture and several weeks of operation may be required to dry it out.

D. Location of the air dryer is too close to the air

compressor. Refer to the Locating Bendix® AD-9® and AD-9® IPC Air Dryer On Vehicle section and Appendix A, Table A, column 2 for discharge line length; or

E. In areas where more than a 30 degree range of

temperature occurs in one day, small amounts of water can accumulate in the air brake system due to condensation. Under these conditions, the presence of small amounts of moisture is normal and should not be considered as an indication that the dryer is not performing properly.

Note: A small amount of oil in the system may be normal

and should not, in itself, be considered a reason to replace the desiccant; oil stained desiccant can function adequately.

2. Check mounting bolts for tightness. Re-torque to 270–385 inch pounds.

3. Perform the Operation & Leakage Tests listed in this publication.

AD-9® / AD-9® IPC

AIR DRYER

END COVER

A two lead, 12 inch, wire harness with attached weather resistant connector is supplied with all retroﬁ t and replacement Bendix Connect one of the two leads of the wire harness to the engine kill or ignition switch. The remaining lead of the wire harness must be connected to a good vehicle ground. A fuse should be installed in the power carrying wire; install a 10 amp fuse for 12 volt heaters and a 5 amp fuse for a 24 volt heater. Use 14 AWG wire if it is necessary to lengthen the wire harness provided. Make certain all wire splices are waterproofed. Tie wrap or support all electrical wire leading to the AD-9® or AD-9® IPC air dryer.

FIGURE 6 - HEATER AND THERMOSTAT CONNECTOR

LOWER

MOUNTING

BRACKET

FEMALE

CONNECTOR

MALE

CONNECTOR

LATCH MUST BE

INSERTED UNTIL

IT SNAPS OVER

TAB ON MATING

CONNECTOR

SIDE VIEW END VIEW

AD-9® and AD-9® IPC air dryers.

water or oil in downstream reservoirs indicate an AD-9® IPC air dryer desiccant cartridge may need to be replaced.

Every 10,800 hours; 300,000 miles or 36 months:

1. Rebuild the air dryer including the desiccant cartridge. Note: The desiccant change interval may vary from vehicle

to vehicle. Although typical desiccant cartridge life is three years, many will perform adequately for a longer period of time. In order to take maximum advantage of desiccant life and assure that replacement occurs only when necessary , it is important that Operation & Leakage T ests be performed.

Oil removal requirements for air brake quality vary by vehicle manufacturer. Because vehicle vocation and maintenance can inﬂ uence when the AD-9® IPC air dryer cartridge requires replacement, each ﬂ eet should modify their replacement schedule based on experience. The change out interval will be extended if the compressor passes a low level of particles, and the interval will be reduced if excessive carbon particles are delivered to the dryer inlet. Higher compressor build up times at idle and

WARNING!

This air dryer is intended to remove moisture and other contaminants normally found in the air brake system. Do not inject alcohol, anti-freeze, or other de-icing substances into or upstream of the air dryer. Alcohol is removed by the dryer, but reduces the effectiveness of the device to dry air. Use of other substances can damage the air dryer and may void the warranty.

OPERATION & LEAKAGE TESTS

1. Test the outlet port check valve assembly by building the air system to governor cut-out and observing a test air gauge installed in the #1 reservoir. A rapid loss of pressure could indicate a failed outlet port check valve. This can be conﬁ rmed by bleeding the system down and removing the check valve assembly from the end cover. Once this has been done, subject air pressure to the unit and apply a soap solution to the check valve side. Leakage should not exceed a 1” bubble in 1 second.

2. Check for excessive leakage around the purge valve. With the compressor in loaded mode (compressing air), apply a soap solution to the purge valve housing assembly exhaust port and observe that leakage does not exceed a 1” bubble in 1 second. If the leakage exceeds the maximum speciﬁ ed, service the purge valve housing assembly.

3. Close all reservoir drain cocks. Build up system pressure to governor cut-out and note that the air dryer purges with an audible escape of air. “Fan” the service brakes to reduce system air pressure to governor cut-in. Note that the system once again builds to full pressure and is followed by an air dryer purge.

4. Check the operation of the safety valve by pulling the exposed stem while the compressor is loaded (compressing air). There must be an exhaust of air while the stem is held and the valve should re-seat when the stem is released.

5. Check all lines and ﬁ ttings leading to and from the air dryer for leakage and integrity.

6. Check the operation of the end cover heater and thermostat assembly during cold weather operation as follows:

A. Electric Power to the Dryer With the ignition or engine kill switch in the ON

position, check for voltage to the heater and thermostat assembly using a voltmeter or test light. Unplug the electrical connector at the air dryer and place the test leads on each of the pins of the male connector. If there is no voltage, look for a blown fuse, broken wires, or corrosion in the vehicle wiring harness. Check to see if a good ground path exists.

B. Thermostat and Heater Operation Turn off the ignition switch and cool the end cover

assembly to below 40 degrees Fahrenheit. Using an ohmmeter, check the resistance between the electrical pins in the female connector. The resistance should be 1.5 to 3.0 ohms for the 12 volt heater assembly and 6.8 to 9.0 ohms for the 24 volt heater assembly.

Some early models of the Bendix

AD-9® air dryer will have resistance readings of 1.0 to 2.5 ohms for the 12 volt heater assembly and 4.8 to 7.2 ohms for the 24 volt heater assembly. If the resistance is higher than the maximum stated, replace the purge valve housing assembly, which includes the heater and thermostat assembly.

Warm the end cover assembly to over 90 degrees

Fahrenheit and again check the resistance. The resistance should exceed 1000 ohms. If the resistance values obtained are within the stated limits, the thermostat and heater assembly is operating properly. If the resistance values obtained are outside the stated limits, replace the purge valve housing assembly, which includes the heater and thermostat assembly.

REBUILDING THE BENDIX® AD-9® AND AD-9® IPC AIR DRYERS

GENERAL

If, after completing the routine operation and leakage tests, it has been determined that one or more components of the air dryer requires replacement or maintenance, refer to the maintenance kit listing in this manual or the Bendix Reference Catalog (BW1 1 14) for complete kit information.

When rebuilding or replacing components of the air dryer, use only genuine Bendix parts. For ease in servicing the Bendix® AD-9® and AD-9® IPC air dryer desiccant cartridge assemblies, it is recommended that the air dryer be removed from the vehicle.

The kit illustrations on the following pages show the kit contents and will be referenced throughout the rebuilding procedures.

BENDIX® AD-9® AND AD-9® IPC AIR DRYER REMOVAL

1. Park the vehicle on a level surface and prevent movement by means other than the brakes.

2. Drain all reservoirs to 0 psi (0 kPa). — Caution: compressor discharge line may still contain residual pressure.

3. Identify and disconnect the three air lines from the end cover and note the position of end cover ports relative to the vehicle. See Figure 1.

4. Unplug the vehicle wiring harness from the heater and thermostat assembly connector on the purge valve housing assembly. See Figure 6.

5. Loosen the 5/16" hex cap screw and sleeve nut securing the upper mounting strap to the upper mounting bracket. See Figure 7, illustration A.

Some air dryers may contain a one piece upper

mounting strap as shown in Figure 7, illustration B. If this is type of strap is present, loosen the adjustment locknut and remove the strap and isolator from the upper bracket.

6. Mark and remove the two 3/8" end cover cap screws, locknuts, and four special washers that secure the lower mounting bracket to the end cover. Also be sure to mark these two holes of the end cover. (These bolts are longer than the other 6 bolts.) Retain the mounting hardware. See Figure 7, illustrations A and B.

7. Remove the air dryer from the vehicle.

Quick

MAINTENANCE KITS

Service New (S) Kit Part Number

107695 S – – –

or Reman

Exchange (RX)

Purge

Valve Type Heater

Connector

Color Kit Description Illustration

Complete Mounting Bracket Kit - Contains the upper and lower brackets as well as the necessary mounting hardware.

5002080 S – – – 5009610 S – – –

107799 S – – –

107800N S – – –

5005037 S Hard Seat – –

5005893 S Soft Seat – –

K041395 S – – – Universal Check Valve Kit E 5003838 S – – – Exhaust Cover Kit F

5004224N S – – – Silencer Kit G

107796 S – – –

107794X RX – – –

K028830 S – – –

109960 S – – –

109961 S – – – Adaptor Kit 800405 S Soft Seat 12V-75W White

5004338 S Soft Seat 24V-75W Gray 5004341X RX Soft Seat 12V-75W White 5004342X RX Soft Seat 24V-75W Gray

5004479 S Hard Seat 12V-75W White

5004480 S Hard Seat 24V-75W Gray

5004381 S Hard Seat 24V-100W Yellow

5004339 S DLU 12V-75W White

5004340 S DLU 24V-75W Gray

5006580 S DLU 24V-100W Yellow

See Catalog

BW1114

109578 S – 12V-75W White 109579 S – 24V-75W Gray

5002595 S – 24V-100W Yellow

109871N S – – – Heater Electrical Splicing Kit M

113209 S – – – Universal Mounting Plate N

S and RX – – – End Cover Replacement K

Mounting Kit B End Cover Check Valve Assembly Replacement -

3/4 inch thread size.

End Cover Check Valve Assembly Replacement -

1/2 inch thread size.

Purge Valve Housing Maintenance Kit - Contains the parts necessary to rebuild the air portion of the purge valve housing and does not include the heater and thermostat.

Desiccant Cartridge Replacement Kit - Contains the parts necessary to change the desiccant cartridge only. Non-IPC Air Dryer

Desiccant Cartridge Replacement Kit - Contains the parts necessary to change the desiccant cartridge only. IPC Air Dryer

Makeup Line Kit

Purge Valve Housing Assembly

(w/heater and thermostat)

Heater and Thermostat Kit L

I5000457 S – – –

SLEEVE

NUT

MOUNTING

SADDLE

LOCKNUT

MOUNTING

STRAP

5/16" HEX

HEAD SCREW

MOUNTING STRAP

ISOLATOR

UPPER BRACKET

ADJUSTING NUT

SPECIAL

WASHER

LOWER

MOUNTING

BRACKET

SPECIAL WASHER

3/8" END

COVER CAP

SCREW

STANDARD MOUNTING BRACKET KIT

SPECIAL

WASHER

3/8" END COVER

CAP SCREW

LOCKNUT

LOWER

MOUNTING

BRACKET

SPECIAL

WASHER

MOUNTING BRACKET KIT

SMALL O-RING

MEDIUM O-RING

LARGE O-RING

QUAD RING

DELIVERY CHECK

VALVE PLUG

(NOT INCLUDED

IN KIT)

SPRING

CHECK VALVE

O-RING

CHECK

VALVE

CHECK VALVE

MAINTENANCE KIT

PURGE VALVE

ASSEMBLY

(NOT

INCLUDED

IN KIT)

WASHER

SCREW

PURGE VALVE HOUSING MAINTENANCE KIT

FIGURE 7 - MAINTENANCE KIT CONTENTS (ILLUSTRA TIONS A THROUGH E)

PISTON

ASSEMBLY

RETURN

SPRING

PURGE

VALVE

EXHAUST

GUIDE

SHOULDER

BOLT

HORIZONTAL

DELIVERY CHECK

VALVE HOUSING

(NOT INCLUDED

IN KIT)

RETAINER

DELIVERY CHECK VALVE KIT

VERTICAL

O-RING

CHECK VALVE

SPRING

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