CAT 054-3939 RETAINER

CAT 054-3939 is a Caterpillar genuine hydraulic pump plunger slipper retainer (pure original factory information, no additional description). It is compatible with high-pressure axial piston pumps for C7/C9 engines (such as the CAT 352-0618 main pump). It is used with the 053-5758 plunger, 053-5759 plunger sleeve, and 053-5834 retainer to lock the slipper and plunger rod, preventing loosening during high-pressure reciprocating motion and ensuring stable pump flow and pressure.

Core Parameters and Information

Item Details
Part Model: CAT 054-3939 (0543939) Slipper Fixer

Type: Elastic snap ring type, axial limiting + circumferential anti-rotation, with positioning boss, adaptable plunger rod annular groove and slipper end face positioning

Material: 65Mn spring steel, surface Dacromet coating + passivation treatment, salt spray and corrosion resistant, hardness HRC40-45, durable elasticity

Key Dimensions: Inner diameter 28 mm, outer diameter 35 mm, thickness 3.2 mm, opening width 2.5 mm, positioning boss height 1.8 mm, adaptable plunger rod diameter 28 mm, weight 0.022 kg

Operating Parameters: Adaptable working pressure ≤35 MPa, temperature resistance -40℃ ～ +120℃, adaptable plunger reciprocating frequency ≤30 Hz

Installation Method After expanding the elastic opening with special snap ring pliers, insert it into the annular groove of the plunger rod, ensuring it fits snugly against the end face of the slipper. After installation, check for any looseness or jamming.

Compatible Models and Assemblies

Compatible Parts: 053-5758 Plunger, 053-5759 Plunger Sleeve, 053-5834 Retainer, 054-0016 Retainer, 352-0618 Main Pump Assembly

Compatible Equipment: CAT 320D/323D/329D excavators, 950H/966H loaders, D6R/D7R bulldozers, etc., equipped with C7/C9 engines.

Matching Parts: 054-3939 Retainer, 053-5760 Return Spring, 053-6530 Bearing, 053-6531 Bearing Retaining Ring

Installation and Maintenance Points
**Before installation, clean the retainer and plunger rod annular groove, ensuring they are free of burrs and oil stains. Inspect the retainer for deformation, cracks, or coating peeling, and ensure normal elasticity.

Use snap ring pliers to evenly expand the opening and insert it into the annular groove, ensuring it fits snugly against the slipper end face, guaranteeing complete embedding without axial movement.

After installation, test the plunger’s reciprocating motion for smooth operation. Perform a high-pressure test to ensure no leakage and stable pressure.

Maintenance: Check elasticity and wear every 2000 working hours. Replace immediately if deformation, cracks, or loosening are observed to prevent plunger assembly failure.