CAT 078-6384 SPOOL ASS’Y

CAT 078-6384 is a Caterpillar genuine hydraulic pilot valve assembly, compatible with the pilot control valve group of 306E/307E excavators and 226B3/246B3 skid steer loaders. It is used to precisely control the direction and flow of movement of actuators such as the boom and stick, ensuring sensitive operational response and stable positioning, and is suitable for continuous operation under medium to low pressure conditions.

Core Parameters and Information

Item Details
Part Model: CAT 078-6384 (0786384) Spool Valve Assembly

Structure Type: Three-position four-way spool valve, including valve core, valve sleeve, spring, seal, locating pin, equipped with 078-5254 locking collar and 078-3392 bearing

Material: Valve core/valve sleeve is 416 stainless steel (hardened HRC 58-62), spring is 65Mn, seal is nitrile rubber (NBR)

Key Dimensions: Valve core diameter 16 mm, stroke 8 mm, valve sleeve inner diameter 16.02 mm, clearance 0.015-0.025 mm, compatible pressure interface G1/4

Performance Parameters: Rated pressure 35 MPa, working pressure 6.3-21 MPa, rated flow 25 L/min, response time ≤100 ms, leakage ≤0.1 mL/min

Compatibility Standard: Complies with ISO 4401, SAE J1276, compatible with 078-0776 pilot valve assembly, 078-5254 locking collar, and 078-3392 bearing.

Compatibility: Compatible with the hydraulic pilot control system of 3044C/3054C engines, 306E/307E excavators, and 226B3/246B3 skid steer loaders.

Compatible Models and Application Scenarios:
Compatible Equipment: Hydraulic pilot control circuits for 306E/307E mini excavators, 226B3/236B3/246B3 skid steer loaders, and 3044C/3054C engines.

Application Scenarios: Installed within the pilot valve assembly, it controls the main valve’s operation by axially sliding the valve core to switch the oil port connection state. Suitable for high-frequency operations such as excavation and loading, ensuring operational efficiency and safety.

Used with 078-5254 locking collar, 078-3392 bearing, and 078-2642 spring to fix the valve core position, reduce friction, and ensure accurate reset.

Installation and Maintenance Points: Clean the valve bore and components. Check the valve core/sleeve for scratches and deformation, ensure the seals are intact, and that the spring has normal elasticity.

Assemble in sequence: First install the spring and seals, then install the valve core and sleeve. Use the 078-5254 locking collar to secure the bearing, ensuring smooth and unobstructed valve core sliding.

Post-installation test: Hold pressure at 35 MPa for 5 minutes without leakage. Valve core stroke should be 8 mm, response time ≤100 ms, and operation should be smooth without jamming or abnormal noise.

Maintenance: Check the seals and valve core for wear every 1000 hours. Replace when wear exceeds 0.05 mm or leakage exceeds 0.5 mL/min. Regularly change the hydraulic oil and filter element.