CAT 419-4723 105.1mm Inner Diameter Sleeve Bearing

The CAT 419-4723 YM is a genuine Caterpillar hydraulic pump end cover assembly, compatible with the hydraulic main pump/pilot pump housing end cover of CAT 320D/336D excavators and 966H loaders. Its core function is to seal the pump body, secure internal bearings and shaft seals, prevent hydraulic oil leakage, and protect internal components from dust and moisture intrusion, ensuring stable and efficient hydraulic system pressure.

Core Technical Parameters

Item Details
Part Model: CAT 419-4723 YM End Cap Assembly, Original Part Number 4194723, YM is the production batch code, no official direct replacement model.

Material: Main body is cast aluminum alloy (ZL109), hardness HB 100-120, lightweight and with good heat dissipation; sealing surface is nitrile rubber (NBR) gasket, oil resistant and temperature resistant from -40℃ to 120℃; fasteners are 8.8 grade high-strength steel bolts to ensure a tight connection.

Key Dimensions: Outer diameter 180mm, inner diameter 80mm, thickness 25mm, bolt hole distribution circle diameter 150mm, number of bolts 6, thread specification M12×1.5, sealing groove width 5mm, depth 2mm, suitable for corresponding hydraulic pump housing mounting positions.

Compatible Models: CAT 320D/336D excavators, 966H/972H loaders, D7R This bulldozer pump uses end covers for the front and rear ends of the hydraulic main pump and pilot pump, as well as the end cover for the rotary motor housing. It is compatible with high-pressure hydraulic systems (working pressure 35MPa) and ensures pump body sealing and internal component positioning.

Performance Features: Lightweight cast aluminum alloy (approximately 1.8kg), with a heat dissipation coefficient of 120W/(m·K); NBR gasket sealing pressure ≥40MPa, suitable for high-pressure conditions; 8.8 grade bolts with tensile strength ≥800MPa, anti-loosening design, suitable for the vibration environment of construction machinery.

Core Functions and Structure:

Sealing Protection: The end cover assembly is tightly fitted to the housing via NBR sealing gaskets, preventing hydraulic oil leakage and preventing external dust and moisture from entering the pump body, avoiding hydraulic oil contamination and internal component wear, and ensuring the cleanliness of the hydraulic system.

Component Fixing: Fixes the internal bearings, shaft seals, and gear/plunger assemblies of the hydraulic pump, ensuring precise component positioning, reducing vibration and noise during operation, and improving pump body operational stability and service life.

Assisted Heat Dissipation: The cast aluminum alloy material possesses excellent heat dissipation properties, helping to dissipate the heat generated during pump operation, reducing hydraulic oil temperature, and preventing problems such as decreased oil viscosity and seal failure due to excessively high oil temperature.

Installation and Maintenance Points
Installation Specifications: Clean the end cover and pump body sealing surfaces, removing oil stains and metal filings. Check that the end cover is not deformed and the sealing gasket is not aged or damaged. The flatness tolerance of the mounting surface should be ≤0.02mm.

During installation, apply CAT 5P-3931 sealant to both sides of the sealing gasket, evenly distributing the bolt preload (tightening diagonally, preload torque 35-40 N·m) to avoid localized stress concentration that could lead to seal failure.

After installation, check the pump body for leaks, start the equipment for trial operation, and observe that the hydraulic oil pressure is stable and there is no abnormal vibration or noise.

Maintenance Recommendations: Every 1000 working hours, check: whether the end cover bolts are loose and whether there is leakage at the sealing surface. If the gasket is aged or the end cover is deformed, replace the end cover assembly promptly.

Regularly change the hydraulic oil and filter element to maintain oil cleanliness (NAS 8 grade), avoid contaminants damaging gaskets and internal components, and extend the service life of the end cap assembly.