Zoomlion Crane Boom Wear Pads and Telescoping Seals

Boom slide pads and telescopic cylinder seal kits for Zoomlion truck cranes. On the QY25V the main boom runs from 10.3 m to 38.5 m, and Zoomlion's lifting tables show how that 28.2 m of travel is split: telescopic cylinder I contributes up to 7.1 m and telescopic cylinder II the remaining 21.1 m. Full extension takes 120 s on the brochure figure, and every cycle drags the sections across their pads. That split matters when ordering — the two cylinders are different parts with different seal kits, and a boom that extends unevenly or will not hold its length points to one stage, not both. The ZTC250V, the 25 t crane that followed, is a different boom: its load moment falls from 960 kN·m on the base boom to 672 kN·m fully extended, against 950 and 525 kN·m on the QY25V, so pads and cylinders are not carried across by tonnage. Pads are identified by section and position — upper, lower and side pads on one section are separate parts, and the pads at the head of one section are not the pads at the tail of the section sliding inside it. Tell us which section shows scoring or metal-to-metal marks and measure the remaining pad thickness; for seals, send the stamping on the cylinder and say whether it is cylinder I or II. A boom that creeps in under load is more often the balance valve on the telescopic cylinder than the seals.