BENDIX TCH-001-051 User Manual

Technical Bulletin

Bulletin No: TCH-001-051 Effective Date: 3/27/03 Cancels: N/A Page: 1 of 1

Subject: BA-921 COMPRESSOR UNLOADER CAP REPLACEMENT KIT

Bendix Commercial Vehicle Systems has determined that for some* BA-921 air compressors, under certain conditions, air pressure can collect above the unloader piston. This prevents the compressor from return to the unloaded mode, causing it to constantly build air. Bendix has determined that this condition is not safety related.

To guard against this occurring, Bendix has developed a replacement unloader cap designed to prevent air being retained above the unloader piston. Bendix recommends that all BA-921 air compressors listed at the bottom of this page have the replacement unloader cap kit installed.

Detroit Diesel Corp. and Caterpillar Inc. will be conducting a service campaign where authorized DDC and CAT service centers will offer unloader cap replacement kits. The kits, Bendix part number 5012771, contain an unloader cap, unloader gasket and spray shield (see Figure 1) along with installation instructions. Replacement should take less than 20 minutes to complete.

BA-921

Spray Shield

Unloader

Cap

Unloader

Gasket

Cylinder

Head

Figure 1:

BA-921 Unloader

Cap

Replacement -

Expanded View

Where a spray shield is already installed, the unloader cap upgrade has already been made, and no action is needed. Only the BA-921 compressors listed below are part of this service campaign.

For any other technical questions, contact your local DDC or CAT Service Center; Call Bendix at 1-800-AIR BRAKE (1-800-247-2725, option 2); or write to Bendix Commercial Vehicle Systems LLC, 901 Cleveland Street, Elyria, OH 44035, Attention: TechTeam.

*Engines and compressor part numbers included in this service campaign:

Engine Engine BA-921 Part Numbers

Manufacturer Type Bendix OE

DDC Series 60 5010821 DDC 23531315

CAT C9 5010803 CAT 191-6521 CAT C15.5, C18 5011427 CAT 223-3637 CAT C11, C13 5011441 CAT 223-3636