CAT 077-2790 RETAINER

CAT 077-2790 is a Caterpillar genuine fuel pump tappet retainer (purely genuine factory information, no additional description). It is compatible with the high-pressure common rail fuel pump tappet assembly of C13/C15/C18 engines, and works with the 069-5112 bushing, 068-8555 retaining ring, and 068-8527 adjusting ring. It is used for radial positioning and axial anti-dislodgement of the tappet shaft end, ensuring the accuracy of the tappet reciprocating motion and stable fuel injection timing, and preventing tappet shaft movement or rotation during pump operation.

Caterpillar Genuine Fuel Pump Tappet Retainer (Pure Genuine Factory Information, No Additional Description) Core Parameters and Information

Item Details
Part Model: CAT 077-2790 (0772790) Tappet Retainer

Structure Type: Combined locking clamp type retainer with positioning slot and bolt mounting holes, blackened surface for corrosion resistance

Material: 40Cr alloy structural steel (quenched and tempered HB220-260, blackened surface, salt spray test ≥96 h), Weight: 0.060 kg

Key Dimensions: Inner diameter 22 mm, outer diameter 42 mm, thickness 9 mm, bolt hole M8×1.25, positioning slot width 3 mm, positioning pin hole φ4 mm

Performance Parameters: Locking torque 22-25 N・m, operating temperature -40℃ to 200℃, radial clamping force ≥1600 N, fatigue life ≥1.2×10⁶ cycles

Compatibility Standard: Complies with CAT 4W-7023 retainer technical specifications, inner diameter tolerance ±0.02 mm, positioning groove tolerance ±0.01 mm
Compatible Models and Assemblies
Compatible Parts: 069-5112 Bushing, 068-8555 Elastic Retaining Ring, 068-8527 Adjusting Ring, 068-6117 Bearing
Compatible Equipment: CAT 336D2L/349D2L Excavator, 980M/982M Loader, D8T/D9R Bulldozer (C13/C15/C18 Engine), used for positioning the end of the high-pressure common rail fuel pump tappet shaft
Installation: 1 piece per tappet shaft, installed at the end of the tappet shaft, fastened with M8 bolts, and cooperates with the retaining ring to achieve axial limit and radial anti-rotation of the tappet shaft.
Installation and Maintenance Points: Clean the mounting surfaces of the retainer and pump body, check for deformation, cracks, and oxide layer peeling, the flatness of the mounting surface ≤0.01 mm, and the roughness Ra≤1.6 μm.

Pre-install the retainer so that the positioning groove engages with the tappet shaft boss. Insert the positioning pin into the pump body pin hole and tighten the M8 bolts to 22-25 N·m, ensuring a tight fit without looseness.

After installation, check that the radial runout of the tappet shaft is ≤0.01 mm, the gap between the retainer and the pump body is ≤0.02 mm, and the fuel pump operates without abnormal noise or leakage.

Maintenance: Check the bolt torque every 2000 hours (re-tighten if below 18 N·m). Replace the retainer if it is deformed/cracked. Simultaneously check the bushings and retaining rings for wear to prevent positioning failure.