CAT 438-6138 29mm Wide Retainer

CAT 438-6138 is a Caterpillar engine fuel system high-pressure fuel line retainer, compatible with Cat C7.1, C9.3 and other engines. It is used for radial positioning and axial loosening of high-pressure fuel lines to prevent displacement, leakage or fatigue fracture caused by vibration. It is a key fastening component of the engine fuel system high-pressure lines in Cat® Parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 438-6138, Type: High-pressure oil pipe clamp, Material: 65Mn spring steel (zinc-plated and passivated), Single weight: approx. 0.05 kg, Applicable temperature: -40℃ to +150℃, Suitable pipe diameter: 12 mm (outer diameter of high-pressure oil pipe), Installation method: Bolt fixing (M8×1.25), Matching bolts: 438-6139, Nuts: 438-6140

Key Dimensions
Clamp body length: 35 mm, Width: 18 mm, Thickness: 5 mm, Clamping groove diameter: 12.2 mm (tolerance +0.10/-0.05 mm), Bolt hole center distance: 25 mm, Clamping groove depth: 8 mm, Clamp body opening width: 6 mm, Surface roughness: Ra≤1.6 μm, Hardness: HRC42-48, Elastic deformation: ≤0.5 mm

Compatible Models and Applications
Compatible with Cat For C7.1 and C9.3 engines (excavator 320GC, loader 950GC, etc.), a high-pressure oil pipe bracket is installed on the cylinder head side to secure the high-pressure oil pipes of cylinders 3 and 4. Each engine requires 6 brackets, and the matching high-pressure oil pipe is 387-9425.

Performance Parameters: Clamping force ≥800 N, fatigue life ≥10⁶ cycles (vibration frequency 10-2000 Hz, acceleration 10 g), salt spray resistance meets ISO 9227 standard (no red rust after 72 hours), oil resistance meets SAE J1885 standard, bolt tightening torque 10-12 N・m.

Structural and Performance Advantages:
Precise clamping design: The clamping groove adopts an arc transition, fitting tightly with the high-pressure oil pipe, avoiding local stress concentration and preventing oil pipe wear; the spring steel material provides lasting elasticity, compensating for vibration displacement and maintaining stable clamping force. Compared with ordinary clamps, the anti-loosening effect is improved by approximately 50%.

Corrosion and Wear Resistance: Galvanized passivation surface treatment effectively resists corrosion from oil and moisture in the engine compartment, extending service life; smooth clamping surfaces reduce relative friction between oil pipes, lowering the risk of leakage.

Standardized Installation: M8×1.25 bolt holes are compatible with universal tools, requiring no special equipment for installation. High positioning accuracy and quick replacement reduce maintenance time and costs.

Suitable for High-Pressure Conditions: Designed specifically for 1600 bar high-pressure fuel systems, meeting the pipe fixing requirements during high engine load operation and preventing safety hazards caused by high-pressure fuel pipe vibration.

Installation and Maintenance Points: Before installation, clean the clamp and fuel pipe surfaces to ensure no oil or impurities are present; align the retainer clamping slot with the high-pressure fuel pipe, align the bolt holes with the cylinder head bracket holes, and tighten the bolts in two stages to the specified torque (5-8 N·m for the first time, 10-12 N·m for the second time) to avoid clamp deformation.

Inspect the retainer’s appearance every 1500 hours of maintenance. If cracks, deformation, or peeling of the galvanized layer are found, replace it immediately. Check the gap between the oil pipe and the clamp. If the gap is greater than 0.2 mm, the retainer needs to be readjusted or replaced to prevent oil pipe vibration.

Prioritize genuine parts. Aftermarket parts must match the material elasticity and clamping precision. Inferior retainers can easily cause oil pipe loosening, leading to fuel leaks, insufficient engine power, and other malfunctions.