CAT 394-6507 SLEEVE

CAT 394-6507 (3946507) is a Caterpillar original equipment manufacturer (OEM) high-pressure fuel line retaining sleeve for engine fuel systems. It is used in 3512/3516B/C series marine/industrial engines to provide radial positioning and vibration isolation for high-pressure fuel lines, preventing fatigue fracture. It is compatible with high-pressure common rail systems, ensuring stable fuel injection pressure (1800-2000 bar).

Core Parameters (Original Manufacturer Nominal)

Item Details
Part Model: CAT 394-6507 (3946507) High-Pressure Oil Pipe Fixing Sleeve (including positioning clamp, rubber buffer ring, lock nut, anti-loosening washer)

Structure Type: Double-claw clamp type, suitable for φ14mm high-pressure oil pipe, built-in NBR rubber buffer ring, M8 external thread locking, installation torque 12-15N・m

Material: Positioning clamp is 6061 aluminum alloy anodized; buffer ring is NBR nitrile rubber (hardness 70±5 Shore A); lock nut is 304 stainless steel; anti-loosening washer is 65Mn spring steel

Key Dimensions: Claw inner diameter 14mm, total width 42mm, total height 36mm, buffer ring thickness 5mm, suitable oil pipe outer diameter tolerance ±0.1mm, mounting hole spacing 32mm

Compatible Objects: 3512/3516B/C This series of marine/industrial engines is compatible with high-pressure common rail systems and matches 10R-7665/10R-7666 high-pressure oil pipes.

Features: Radial positioning accuracy ±0.2mm, vibration isolation efficiency ≥80% (5-500Hz), oil temperature resistance -40℃ to 120℃, working pressure 0-2500bar, protection rating IP54.
Weight: Approx. 0.18kg.
Applications:
Installation and Positioning: Mounted on a fixed bracket on the engine cylinder head side. The clamps hold the high-pressure oil pipe, rubber buffer rings isolate vibration, lock nuts secure the clamp position, and anti-loosening washers prevent thread loosening. Each high-pressure oil pipe comes with two sleeves (one for the inlet and one for the outlet).

Operating Conditions: Suitable for continuous high-load conditions such as marine propulsion and power plant backup. The lightweight aluminum alloy design reduces the load on the bracket, and the rubber rings absorb high-frequency vibrations (1000-2000Hz) of the injection system, preventing stress concentration at the oil pipe joints. Compatibility: Compatible with 10R-7665 high-pressure oil pipe and 394-6508 fixed bracket. During replacement, simultaneously check for aging of the buffer ring, deformation of the clamps, and damage to the nut threads.

Installation and Maintenance Points
Installation Steps:
Clean the surface of the oil pipe and the sleeve. Place the buffer ring onto the oil pipe, align the clamps with the oil pipe and engage them in the bracket mounting slot. Pre-tighten with an M8 nut.
Adjust the sleeve spacing (one sleeve every 150-200mm), tighten with a torque wrench to 12-15 N·m, install anti-loosening washers, and check for radial looseness in the oil pipe and for any compression deformation of the buffer ring.

Maintenance Cycle: Check every 1500 hours under standard operating conditions; shorten to 800 hours under harsh operating conditions (high temperature/high vibration). Focus on checking for aging of the buffer ring (cracks/hardening), loosening of the clamps, and stripped nut threads.

Replacement criteria: If the buffer ring is cracked/hardness changes by more than 10 Shore A, the jaws are deformed by more than 0.3mm, the nut is stripped, or the positioning accuracy is out of tolerance, the entire unit must be replaced and cannot be repaired or continued to be used.