Technical Bulletin
Bulletin No: TCH-008-032-A Effective Date: 11/29/99 Cancels: NA Page: 1 OF 2
Subject:
It has been brought to our attention that there was a manufacturing defect in a small number of AD-SP and AD-IS
air dryer cartridges. The defective air dryer cartridges may allow desiccant beads to pass from the cartridge into
the purge valve assembly of the air dryer. If the desiccant becomes trapped in the purge valve assembly, the
purge valve may be prevented from closing completely, causing the system to leak charge air to atmosphere. This
leakage of air will then result in the inability to build system air pressure.
The table on page two identifies suspect piece numbers and their corresponding date codes. The defect has been
corrected, therefore all components manufactured on or after November 13, 1999 (L1399H) are not suspect.
1. If the system is unable to build air pressure, inspect the air dryer for leakage around the purge valve during
2. Refer to instruction sheets provided in the maintenance kits where applicable.
3. Using shop air, remove all desiccant material from the air dryer body assembly. Caution: Wear proper eye
4. Wipe all of the body bores clean with a clean rag.
5. Install the air dryer cartridge.
6. Install the purge valve assembly and test per the installation instruction sheet.
AIR DRYER CARTRIDGE DEFECT
the charge cycle. Wear appropriate eye protection and review all caution notes printed in the service manual
for the appropriate air dryer (SD-08-2415 for the AD-SP or SD-98-9808 for the DRM with AD-IS).
a. Use a strap wrench to remove the cartridge. Position the strap wrench next to the lower lip of the
cartridge to prevent cartridge damage. Turn the cartridge counterclockwise to remove.
b. If desiccant beads are present in the purge valve area, the air dryer cartridge and purge valve assembly
must be replaced. See page two for service replacement piece numbers.
c. Re move the purge valve snap ring and purge valve assembly.
protection when using compressed air to blow the desiccant out of the air dryer body assembly.
a. Lubricate the cartridge sealing ring with lubricant provided.
b. Screw the desiccant cartridge on to the body, by hand, clockwise until the seal makes contact with the
body. Turn one full turn. If necessary, place a strap wrench on the desiccant cartridge next to the lower
lip of the cartridge.
The piece numbers that are suspect are shown below with their respective date codes. Also shown are the
appropriate cartridge and purge valve assembly piece numbers to be used for servicing the air dryer. Ensure the
date code of the component you are using for service does not fall within the defective range.
Suspect Piece Numbers and Service Replacements
Description Defective Component
Date Code
AD-SP H2399H – L1299H
(8/23/99 – 11/12/99)
AD-IS All dates through L1299H
(11/12/99)
Cartridge Kit
(Truck Prod.)
Cartridge Kit H2399H – L1299H
J2599H – L1299H
(9/25/99 – 11/12/99)
(8/23/99 – 11/12/99)
Suspect
Piece
Numbers
065691
065694
109872
131031
131032
800042
800043
5000104
5000445
5000587
5002747
5002748
5006639
800383
5003424
BR950011 BR950011 N/A
109994 109994 N/A
Cartridge
Service
Replacement
Piece Numbers
109994 109995
109994 800404
Purge Valve
Assembly Service
Replacement
Piece Numbers
Return all defective or suspect piece numbers to:
Truck Brake Systems Co.
1850 Riverfork Dr. West
Huntington, IN 46750
Phone 1-800-247-2725