Description
BA-921 CAT AIR BRAKE COMPRESSOR (REMANUFACTURED)
PART NUMBER(S):
Fleet Products: 5012533X (Remanufactured) 5012533N (New) | Replaces OE: Bendix 5011427, 5011427X, 5011441, 5012459, 5012464, 5012510, 5012531, 5012531X, 5012532, 5012532X, 5012533, 5012533B1, 5012533BXR, 5012533C, 5012533N, 5012533X, 5012533X-C, 5014177, 5014180, 5014235, 5014236, 5014401, 5014402, 5014427, 5014428, 801463, 801465, 801798, 801826, K020283, K020284, K020285, K048938, K048939, K048940, K048941, K048942, K048943, K056646, K056647, K056649, K066811, K066812, K066831, K066832, K066837, K066838, K209254, K209255, K209328, K209329 | CAT 0R-1623, 0R-1624, 0R1624, 10R-9375, 10R9375, 20R-0177, 20R-0178, 20R0176, 20R0178, 223-3636, 223-3637, 2233637, 253-1736, 255-4160, 304-9991, 3049991, 353-7136, 353-7137, 3537137, 385-0935, 385-0936, 385-0937, 3850937 | Navistar 3861777C91, K041109, K055513, K055514 | Mack 745-5012533, 745-5012533X, 7455012533, 7455012533X, 745X-5012533, 745X5012533
DESCRIPTION:
Model: BA-921 40-tooth air brake compressor with external oil line
Vehicles: Caterpillar C15/C18 ACERT engines, pre-2007, Detroit Series 60 EGR engines, 2002–2006
• Bore x Stroke: 3.622 in x 2.126 in
• Unloader Line Size: 3/16 in ID
• Inlet Port Fitting: M27 x 2, 991–1089 in-lb
• Discharge Port Fitting: M22 x 1.5, 814–912 in-lb
• Water Port Fitting: M18 x 1.5, 593–637 in-lb
• Oil Port: 7/16"-16 UNF, 150–170 in-lb
• Unloader Port: 1/8"-27 NPT, 2–3 turns from finger tight
• Safety Valve Port: 7/8"-14, Bendix ST-4 801116 not included
• Air Inlet: Top-mounted
• Air Outlet: Side-mounted
• Mounting: Flange mount, direct engine mounting
• Cooling: Air and water cooled
• Cylinders: 1, 358 CC
• Displacement: 15.8 CFM at 1250 RPM
• Flow: 11.6 CFM at 1800 RPM / 120 PSI; 16.5 CFM at 3000 RPM / 120 PSI
• Power: 4.6 HP loaded / 0.8 HP unloaded at 1800 RPM / 120 PSIG
• Minimum Coolant Flow: 1.5 GPM at maximum RPM
• Minimum Oil Pressure: 15 PSI
• Minimum Governor Cut-Out: 120 PSI
• Temperature: 170°F inlet / 400°F discharge
• Torque: M8 cylinder head 265–292 in-lb; M8 governor adapter 195–213 in-lb; M10 rear end cover 195–213 in-lb
• Includes: Installation gaskets and O-rings
CROSS-REFERENCE(S):
046255012533X, 165-179-9212, 1651799212, 170.AC5012533, 20R0176, 20R0178, ABP N13AC 20R0178, BAR5012533, BC1-25566, CAT 20R-0178, EX5012533X, H5011427X, H5012533X, HVG5012533X, MID5012533X, OR1624, R9555012533X
A cross-reference listing means this part should be a suitable replacement for the part numbers listed.
IMPORTANT INSTALLATION NOTES:
✔ Always inspect or replace discharge line from compressor head
✔ Avoid sharp bends, restrictions, or damaged air lines
✔ Follow CAT or OE torque specs and gasket guidelines for proper sealing
✔ Confirm compatibility with specific C15/C18 engine casting and mounting
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
