BENDIX TCH-001-060 Manual Do Utilizador
Technical
Bulletin
Bulletin No:
Effective Date:
Cancels:
Page: 1 of
Subject:
This bulletin is in reference to Bendix
®
BA-921
®
and BA-922
®
compressors installed on Detroit Diesel DD15
™
and DD13
™
engines. These compressors contain an Energy Saving System (ESS) within the cylinder head
that may require servicing while the compressor is still covered under warranty. The life expectancy of the
ESS varies according to the vehicle vocation and duty cycle. High air usage systems will result in reduced
life of the compressor ESS. In such cases, the ESS can be diagnosed for leakage and replaced if necessary.
ESS varies according to the vehicle vocation and duty cycle. High air usage systems will result in reduced
life of the compressor ESS. In such cases, the ESS can be diagnosed for leakage and replaced if necessary.
This bulletin details the proper diagnostic and replacement procedures for the ESS. Failure to follow these
procedures may result in a denied warranty claim if the ESS portion of the compressor, submitted
for warranty consideration, is deemed causal. Note that if excessive carbon is present in the discharge
fi tting of the compressor, with a fi lm greater than 10% of the inside diameter, the entire compressor should
be replaced.
procedures may result in a denied warranty claim if the ESS portion of the compressor, submitted
for warranty consideration, is deemed causal. Note that if excessive carbon is present in the discharge
fi tting of the compressor, with a fi lm greater than 10% of the inside diameter, the entire compressor should
be replaced.
If the nature of the compressor issue, or complaint, is any of the following; the ESS is the likely source
(assuming that checks for other system malfunctions have been carried out).
(assuming that checks for other system malfunctions have been carried out).
(A) ESS leaking when pressurized
(D) Compressor not unload
(B) Compressor safety valve popping off
(E) System will not build air pressure
(C) Air dryer purge valve and compressor
(F) System slow to build
cycling rapidly
(G) Compressor leaking air
DIAGNOSING THE UNLOADER SYSTEM FOR PROPER OPERATION AND PRESSURE SETTING
When performing any service, be sure to follow all safety guidelines outlined in the BA-921
®
or BA-922
®
compressor service data sheets, SD-01-690 or SD-01-700, or instruction sheet as applicable.
1. Using shop air, pressurize the unloader line to 120 psi and check for leaks in this line. Remove the air
pressure and ensure the unloader line is properly seated in the governor fi tting. Using shop air, check the
unloader line, again, for leaks. If there are no leaks, return the vehicle to service. If a leak is still present,
go to step 2.
unloader line, again, for leaks. If there are no leaks, return the vehicle to service. If a leak is still present,
go to step 2.
2. Remove the compressor from the vehicle and closely inspect for any non-ESS related issues. If there are
non-ESS issues, submit the compressor for warranty consideration.
3. If there aren’t any obvious non-ESS related issues, service the ESS using the ESS service replacement
kit as outlined in this bulletin.
TCH-001-060
1-13-2011
TCH-001-060 dated 12-2-2010
4
ESS REPLACEMENT FOR BENDIX
®
BA-921
®
& BA-922
®
COMPRESSORS - REVISED
Continued...
Supply
Reservoir
Closed Room Compressor Typical System
Compressor
Governor Unloader
Port
Air Dryer
Governor
Reservoir Port
Purge Valve
Cycling