Description
BA-921 DETROIT AIR COMPRESSOR 1 3/4" INLET REMANUFACTURED
PART NUMBER(S):
Fleet Products: K031987X (Remanufactured) | Replaces OE: Detroit Diesel / Mercedes: A4721300015, A4721300515, A4721300815, EA4721300815, RA4721300815, A0011304915, 4721300815 | Bendix: K020253, K020801, K031986, K031986SC, K031987, K095124, K095740 | Automann: 170.ACK031987, 170.ACK031987D
DESCRIPTION:
Model: Bendix BA-921 Detroit Air Brake Compressor
Vehicles: Detroit Diesel DD13/DD15 (2007 EPA HDEP), Freightliner Cascadia, Western Star, Mercedes OM472, MBE900 applications
• Configuration: Closed room head
• Air inlet: 1-3/4 in inlet
• Mounting: Flange mount
• Drive: Engine driven with thru-drive support
• Cylinders: 1
• Bore × Stroke: 3.622 in × 2.126 in
• Rated displacement: 15.8 CFM @ 1250 RPM
• Flow: 11.6 CFM @ 1800 RPM / 120 PSI
• Flow: 16.5 CFM @ 3000 RPM / 120 PSI
• Power requirement: 4.6 HP loaded / 0.8 HP unloaded @ 1800 RPM / 120 PSIG
• Minimum coolant flow: 1.5 GPM
• Minimum oil pressure: 15 PSI
• Minimum governor cut-out pressure: 120 PSI
• Minimum unloader line I.D.: 3/16 in
• Temperature range: 170°F inlet / 400°F discharge
• Cylinder head fastener torque: 265–292 in-lb
• Governor adapter fastener torque: 195–213 in-lb
• Rear end cover fastener torque: 195–213 in-lb
• Inlet port fitting: M27 × 2, 991–1089 in-lb
• Discharge port fitting: M22 × 1.5, 814–912 in-lb
• Water port fitting: M18 × 1.5, 593–637 in-lb
• Oil port fitting: 7/16-16 UNF, 150–170 in-lb
• Unloader port fitting: 1/8-27 NPT, 2–3 turns from finger tight
Applications:
Designed for Detroit Diesel DD13 and DD15 EPA 2007 engine applications requiring a Bendix BA-921 air brake compressor. Supplies compressed air for heavy-duty air brake and auxiliary pneumatic systems using the original closed room head, flange mount, and thru-drive configuration.
CROSS-REFERENCE(S):
A4721300015, A4721300515, A4721300815, EA4721300815, RA4721300815, A0011304915, 4721300815, K020253, K020801, K031986, K031986SC, K031987, K095124, K095740, 170.ACK031987, 170.ACK031987D, 710383AT, HDXK031987X, HDX K031987X, 170ACK031987
A cross-reference listing means this part may be a suitable replacement for the listed part numbers. Always verify fitment before installation.
IMPORTANT INSTALLATION NOTES:
✔ Maintain minimum coolant flow of 1.5 GPM
✔ Confirm external oil supply line is connected before startup
✔ Verify air, oil, and coolant fittings are properly sealed before operation
✔ Drain air reservoirs before servicing air brake components
✔ Replace all mounting gaskets and sealing components during installation
✔ Check for air, oil, and coolant leaks after the system reaches operating pressure
✔ Torque all fasteners and fittings to the specified values before returning the vehicle to service
SOLD AS REMANUFACTURED – CORE RETURN REQUIRED
Built to OEM standards — thoroughly cleaned, inspected, and tested to ensure durability, performance, and reliability in demanding applications.
Warranty Information
