BENDIX TCH-008-028 Manuale Utente
Technical
Bulletin
Bulletin No: TCH-008-028
Effective Date: 11/17/97
Cancels: TCH-008-027
Page: 1 of 5
Subject:
AD-9DI & AD-IP Purge Valve Upgrade
GENERAL
This is to announce the availability of new upgraded purge valve assemblies for the AD-9DI Drop-In and AD-IP
air dryers.
This is to announce the availability of new upgraded purge valve assemblies for the AD-9DI Drop-In and AD-IP
air dryers.
Note: The AD-9DI is a specialized version of the AD-9 which is specifically designed for air systems where
the Holset (Cummins) type E or QE compressor was in use. See figure 3.
Bendix Commercial Vehicle Systems LLC began using the new purge valve assemblies in production on
November 1, 1997.
November 1, 1997.
Because of the improvements made to the new purge valve assemblies we recommend that all affected AD-9DI
and AD-IP air dryers be upgraded with the new purge valve subassemblies. Upgrades for in-service air dryers, as
well as shelf stock of purge valve kits and service new and remanufactured exchange air dryers are available free
of charge when the return procedure described in this bulletin is followed. Bendix strongly encourages all
customers to take advantage of this valuable upgrade offer.
and AD-IP air dryers be upgraded with the new purge valve subassemblies. Upgrades for in-service air dryers, as
well as shelf stock of purge valve kits and service new and remanufactured exchange air dryers are available free
of charge when the return procedure described in this bulletin is followed. Bendix strongly encourages all
customers to take advantage of this valuable upgrade offer.
THE FOLLOWING TOPICS ARE COVERED IN THIS BULLETIN.
• SUMMARY OF PURGE VALVE ASSEMBLY IMPROVEMENTS
• SUMMARY OF PURGE VALVE ASSEMBLY IMPROVEMENTS
• PART NUMBER CHANGES
• WHAT IS ELIGIBLE FOR REPLACEMENT
• IDENTIFYING IN-SERVICE AIR DRYERS WITH LATEST PURGE VALVE ASSEMBLY
• OBTAINING A REPLACEMENT
SUMMARY OF PURGE VALVE ASSEMBLY IMPROVEMENTS
AD-IP Air Dryer Purge Valve Assemblies
The AD-IP purge valve assembly has been upgraded for improved temperature resistance. The changes which will
eliminate recently reported incidents of intermittent sticking are:
1. A heavier purge piston return spring to assure positive closing.
2. A modified piston and seal combination for improved sealing at higher temperatures.
The AD-IP purge valve assembly has been upgraded for improved temperature resistance. The changes which will
eliminate recently reported incidents of intermittent sticking are:
1. A heavier purge piston return spring to assure positive closing.
2. A modified piston and seal combination for improved sealing at higher temperatures.
AD-9DI Drop-In Air Dryer Purge Valve Assemblies
The AD-9DI purge valve assembly has been upgraded for improved temperature resistance required for Holset
(Cummins) compressors which produce higher discharge temperatures. The changes which will eliminate recently
reported incidents of intermittent sticking are:
1. A heavier purge piston return spring to assure positive closing.
2. A modified piston and seal combination for improved sealing at higher temperatures.
The AD-9DI purge valve assembly has been upgraded for improved temperature resistance required for Holset
(Cummins) compressors which produce higher discharge temperatures. The changes which will eliminate recently
reported incidents of intermittent sticking are:
1. A heavier purge piston return spring to assure positive closing.
2. A modified piston and seal combination for improved sealing at higher temperatures.