CAT 8W-0038 200.34mm Inner Diameter Mount Cap

CAT 8W-0038 is a Caterpillar threaded pipe cap, suitable for sealing hydraulic lines, fuel systems, and lubrication systems. It is used to seal unused interfaces, protect threads, prevent impurities from entering and fluid leakage, and is a commonly used basic Cat® Part for hydraulic/fuel system maintenance. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 8W-0038, Type: Threaded Pipe Plug, Material: Low Carbon Steel (Galvanized and Passivated Surface, Salt Spray Resistance ≥240 h), Single Weight: Approx. 0.05 kg, Suitable Temperature: -40℃ to +120℃, Sealing Method: Threaded Seal + O-ring (Nitrile Rubber 90A), Installation Tool: 14 mm Socket Wrench

Key Dimensions
Thread Specification: 1/4″-18 NPT (Tapered Pipe Thread, Reliable Seal), Outer Diameter: 19 mm (Tolerance h6), Height: 12 mm (Tolerance ±0.1 mm), Inner Diameter: 6 mm, O-ring Outer Diameter: 14 mm, Wire Diameter: 2 mm

Applicable Models and Locations
Applicable to: Cat 320D/323D Excavator Hydraulic Oil Tank Return Port Plug, 950GC Loader Fuel System Bleed Port, D6K Bulldozer lubrication system branch plugs, 3-5 pieces per unit, used to seal idle pipe interfaces, protecting threads and keeping the system clean.

Performance Parameters: Maximum working pressure 35 MPa, thread sealing torque 12-15 N·m, O-ring oil resistance temperature -30℃ to +100℃, suitable for hydraulic oil, diesel oil, engine oil, and other media.

Structural and Performance Advantages:

Double sealing for reliable performance: Tapered pipe thread + nitrile O-ring combination, combining thread self-sealing and rubber elastic sealing, suitable for high-pressure conditions, preventing fluid leakage and air ingress.

Corrosion-resistant and durable: Low-carbon steel material + galvanized passivation treatment, resistant to moisture and chemical corrosion, suitable for dusty and humid outdoor conditions of construction machinery, extending service life.

Easy installation: Standard NPT thread, no special tools required, manually pre-tighten and then tighten with a socket wrench to the specified torque, high installation efficiency, suitable for quick maintenance needs.

High versatility: Compatible with various Cat… The hydraulic, fuel, and lubrication systems of this model can be used as universal spare parts, reducing inventory types and lowering procurement costs.

Installation and Maintenance Points: Before installation, clean the threaded interfaces to remove oil and impurities, and check the O-rings for damage. Apply a small amount of thread sealant (Loctite 567) to the threads, manually screw it in 2-3 turns, and then tighten it with a socket wrench to 12-15 N·m to ensure a leak-free seal.

Maintenance every 1000 hours: Check the pipe plugs for looseness and leaks. If the threads are rusted or the O-rings are aged, replace them promptly. Avoid using excessive force during disassembly to prevent thread damage.

Prioritize genuine parts. Aftermarket parts may have insufficient thread precision or substandard O-ring material, easily leading to seal failure and causing hydraulic/fuel system leaks.