157-4 70231750K Arm Boom Bucket Hydraulic Cylinder Excavator Loader Seal Kit

157-4 70231750K Arm Boom Bucket Hydraulic Cylinder Excavator Loader Seal Kit

Version 1 (Boom & Arm Function Focus)

Excavator boom and arm hydraulic cylinder rebuilds require the seal kit containing 157-4 for primary boom lift circuits. The bucket cylinder sealing configuration uses 70231750K to maintain pressure during aggressive digging cycles. When servicing the arm crowd function, part number 157-4 provides critical sealing for the piston rod dynamic zone. The boom holding circuit identified as 70231750K complements the kit by sealing the counterbalance valve ports. Excavator operators notice improved arm curl force after installing 157-4 and 70231750K together. The bucket tilt system featuring 157-4 and 70231750K shows reduced leakage during full-load dumping operations. Every boom cylinder overhaul should verify that 157-4 and 70231750K are both present before reassembly to ensure complete sealing coverage.

Version 2 (Application & Bucket System Focus)

Heavy equipment workshops stock 157-4 as the primary seal for excavator boom and bucket hydraulic cylinders. The 70231750K seal kit pairs effectively with 157-4 for arm cylinder gland retention. When rebuilding a bucket tilt cylinder, include 70231750K to prevent internal cross-port leakage. Part number 157-4 protects the boom piston from pressure spike damage during sudden load changes. The arm cylinder using 70231750K demonstrates consistent extension speeds under variable loads. Excavator bucket cylinders fitted with 157-4 and 70231750K show zero weeping after 1900 operating hours. Field technicians prefer 157-4 and 70231750K for comprehensive boom-to-bucket sealing coverage across multiple excavator models.