CAT 077-8340 SEAT CHECK

CAT 077-8340 is a Caterpillar genuine hydraulic system pressure test fixture (pure original factory information, no additional description), used for hydraulic circuit pressure testing and rapid diagnosis. It is compatible with medium and high pressure hydraulic systems and features reliable sealing and easy installation.

Core Parameters and Information

Item Details
Part Model: CAT 077-8340 (0778340) Pressure Test Port/Inspection Port

Structure Type: Integrated pressure test connector with dust cap, internal thread connection, compatible with standard pressure test hose

Material: Carbon steel body, galvanized and passivated surface; seal is nitrile rubber (NBR)

Key Dimensions: Interface thread is 1/4-18 NPTF, total length approximately 45 mm, mounting thread is M16×1.5, compatible mounting hole diameter is 16 mm

Performance Parameters: Rated working pressure 35 MPa, burst pressure 105 MPa, operating temperature -20℃ to +80℃, seal hardness 70±5 Shore A

Compatibility Standard: Complies with SAE J1926-1 pressure test connector specification, compatible with CAT standard pressure test tools

Accessories: Includes 1 dust cap, compatible with CAT 5P-7227 Pressure Testing Hoses for Use

Compatible Models and Application Scenarios

Compatible Equipment: Hydraulic systems of CAT 320/336 series excavators, 950/966 series loaders, 420/430 series mini loaders, etc.

Application Scenarios: Pressure detection points such as hydraulic pump outlets, main control valves, and cylinder circuits. Used for quick connection to pressure testing instruments to diagnose abnormal system pressure and ensure normal equipment operation.

Installation: Install at the preset interface on the hydraulic pipeline or valve block, tightening via thread. Installation torque: 25-30 N·m.

Installation and Maintenance Points: Clean the mounting threads and sealing surfaces. Check the test seat for cracks and thread damage, and confirm interface compatibility.

Screw the test seat into the mounting hole and tighten with a torque wrench to 25-30 N·m, ensuring a good seal and no leakage.

Post-Installation Testing: Connect the pressure testing hose, turn on the hydraulic system, and check that the pressure display is normal and there are no leaks. The dust cap must be replaced promptly to prevent impurities from entering.

Maintenance: Check the seal and thread condition every 200 hours; replace seals promptly if they are aged or damaged to prevent high-pressure leaks from causing safety accidents.