Sany Cylinder Assy-Boom-Telescoping

The Sany Cylinder Assy-Boom-Telescoping is a complete OEM hydraulic actuation system that powers the extension and retraction of multi-section telescopic booms on Sany heavy truck cranes and all-terrain cranes.

This Sany Cylinder Assy-Boom-Telescoping integrates two matched hydraulic cylinders that work in a master‑slave configuration to deliver synchronized and precise boom movement. When you need authentic replacement components, trust Sany Parts to deliver factory-original quality and precise fitment.

The Sany Cylinder Assy-Boom-Telescoping is specifically designed for Sany STC‑series truck cranes and SAC‑series all‑terrain cranes with 4‑section or 5‑section telescopic booms, ensuring smooth, controlled extension under full rated loads.

Sany Cylinder Assy-Boom-Telescoping — OEM telescoping cylinder assembly for Sany heavy truck cranes and all‑terrain cranes

What is the Sany Cylinder Assy-Boom-Telescoping?

The Sany Cylinder Assy-Boom-Telescoping is a matched pair of hydraulic actuators that provide the motive force for extending and retracting the telescoping sections of Sany heavy lifting booms. This twin‑cylinder design enables the smooth, synchronized movement of multiple boom sections under full load.

The Sany Cylinder Assy-Boom-Telescoping comprises two precision‑engineered cylinders: Telescopic boom oil cylinder Ⅰ (10047023) and Telescopic boom oil cylinder Ⅱ (10047028). These cylinders are arranged in a master‑slave hydraulic circuit where the primary cylinder controls the extension while the secondary cylinder provides synchronization and additional force.

The Sany Cylinder Assy-Boom-Telescoping is a critical component for crane productivity and safety. It ensures that all boom sections extend and retract at the same rate, preventing internal binding that could damage the boom structure or cause uncontrolled load movement. The integrated holding valves lock the boom at any length, preventing unintended retraction even if hydraulic pressure is lost.

The Sany Cylinder Assy-Boom-Telescoping is a direct replacement for worn or damaged telescoping cylinders on Sany STC‑series truck cranes and SAC‑series all‑terrain cranes with 4‑section or 5‑section telescopic booms. By using this genuine assembly, you ensure that the cylinder bore, stroke, and mounting dimensions match factory specifications, eliminating synchronization issues that lead to uneven extension speeds and structural stress.

Product Parameters of Sany Cylinder Assy-Boom-Telescoping

Technical specifications: The Sany Cylinder Assy-Boom-Telescoping is engineered for operating pressures up to 35 MPa (5,075 psi) with a flow capacity matched to Sany crane hydraulic systems. Cylinder Ⅰ typically serves as the master cylinder with a larger piston area, while Cylinder Ⅱ acts as a slave cylinder that provides synchronization and additional force.

Both cylinders are manufactured from high‑strength seamless steel tubes with honed internal surfaces (0.2 μm Ra finish) and hard‑chrome‑plated piston rods (25 μm thickness). Each cylinder is equipped with integral holding valves that prevent unintended retraction and maintain boom position even if hydraulic pressure is lost. The cylinder bodies are painted with Sany’s multi‑layer epoxy‑polyester coating for corrosion resistance.

All components of the Sany Cylinder Assy-Boom-Telescoping are manufactured under ISO 9001:2025 certification and are 100% pressure‑tested before leaving the factory. The assembly has been validated on Sany STC and SAC series cranes operating globally, demonstrating a field service life exceeding 10,000 operating hours under heavy‑duty lifting conditions when properly maintained.

Why Choose Our Sany Cylinder Assy-Boom-Telescoping?

Matched Master‑Slave Cylinder Pair — Perfect Synchronization: The Sany Cylinder Assy-Boom-Telescoping includes both Cylinder Ⅰ and Cylinder Ⅱ as a matched set, with internal clearances and flow characteristics calibrated together at the factory. This ensures that the cylinders extend and retract at identical speeds, eliminating the uneven boom movement that causes internal binding and accelerated wear.

Integral Holding Valves for Load‑Locking Safety: The Sany Cylinder Assy-Boom-Telescoping incorporates pilot‑operated holding valves that lock the boom at any extension length, preventing unintended retraction even if the supply line is ruptured. This fail‑safe feature is essential for crane safety, maintaining load position during lifting operations and preventing sudden boom collapse.

Superior Seal Technology for Leak‑Free Operation: The Sany Cylinder Assy-Boom-Telescoping uses multi‑element sealing systems with polyurethane primary seals, PTFE backup rings, and abrasion‑resistant wear guides. This combination ensures zero external leakage and maintains cylinder efficiency over thousands of operating hours, even under the extreme pressure spikes common in telescoping circuits.

Fleet‑Proven Reliability and Comprehensive Warranty: The Sany Cylinder Assy-Boom-Telescoping is standard equipment on Sany STC‑series truck cranes and SAC‑series all‑terrain cranes in over 100 countries. Fleet data shows that genuine Sany telescoping cylinders deliver an average service life exceeding 10,000 hours—three times longer than generic aftermarket cylinders—while eliminating synchronization failures and internal leakage incidents.

The assembly is backed by a 24‑month manufacturer’s warranty covering cylinder weld integrity, seal leakage, piston rod scoring, and holding valve failure. Volume pricing, consignment stock, and global technical support are available for large fleets.

What are the Routine Maintenance Considerations for the Sany Cylinder Assy-Boom-Telescoping?

Daily visual inspection before operation: Before each shift, inspect the Sany Cylinder Assy-Boom-Telescoping for visible hydraulic leaks around the rod seals, cylinder head, and holding valve connections. Check the piston rods for any signs of scoring, pitting, or chrome flaking. Inspect the cylinder mounting bolts for tightness and check for any unusual axial play at the pin connections.

Hydraulic fluid quality and filtration — every 500‑1,000 hours: The Sany Cylinder Assy-Boom-Telescoping requires hydraulic fluid cleanliness of ISO 4406:2017 code 18/16/13 or better. Contaminated fluid is the leading cause of seal wear and valve sticking. Take fluid samples every 1,000 hours for particle count analysis. In dusty environments, increase the fluid change interval to every 500 hours and replace all return line filters. Maintain fluid viscosity within the recommended range (ISO VG 46 for normal conditions, ISO VG 32 for cold climates).

Telescoping function test and cylinder synchronization check — every 1,000 operating hours: Extend and retract the Sany Cylinder Assy-Boom-Telescoping through its full range of motion while observing extension and retraction speeds. Any section that extends or retracts more slowly than others indicates a synchronization issue, internal leakage, or damaged holding valve. If cylinder response is sluggish, check the holding valve for pilot pressure loss and inspect the cylinder piston seals for bypass.

Preventative overhaul schedule — every 4,000 hours or 2 years: For high‑use cranes, Sany recommends a full overhaul of the Sany Cylinder Assy-Boom-Telescoping every 4,000 operating hours or 2 years. Replace both cylinders’ seal kits, including the rod seal, piston seal, wear rings, and wiper seals. Inspect the holding valves for internal wear and replace them if any leakage is detected. Inspect the piston rod for scoring; if scoring exceeds 0.2 mm, replace the cylinder assembly. Keep a detailed maintenance log tracking fluid change dates, seal replacement history, and cylinder test results. By following this proactive schedule, the Sany Cylinder Assy-Boom-Telescoping can reliably exceed 10,000 operating hours.

Telescopic boom oil cylinder Ⅰ (10047023) is typically the master cylinder in the telescoping circuit. It has a larger piston diameter and provides the primary force for extending the heaviest boom sections. The cylinder is equipped with a pilot‑operated check valve that locks the boom in position when the control valve is in neutral, preventing load creep.

Telescopic boom oil cylinder Ⅱ (10047028) is the slave cylinder. It is hydraulically connected in series with the master cylinder, ensuring that both cylinders extend at the same rate despite any load imbalances. The slave cylinder also includes a counterbalance valve that controls the retraction speed, preventing uncontrolled collapse of the boom when hydraulic pressure is released.

The Sany Cylinder Assy-Boom-Telescoping is designed for high‑frequency telescoping operations typical of construction sites, where the boom may be extended and retracted dozens of times per day. The piston rods are induction‑hardened to a depth of 1.5 mm with a hard chrome plating that resists corrosion and scoring. The cylinder tubes are honed to a surface finish of 0.2 μm Ra, minimizing seal wear and reducing internal friction.

For Sany cranes operating in extreme cold climates (below -25°C), special considerations apply to the Sany Cylinder Assy-Boom-Telescoping. Use low‑viscosity hydraulic fluid (L‑HV22 or L‑HV32) to ensure adequate flow and pilot pressure during cold starts. Allow the engine to idle for 10‑15 minutes before operating the telescoping function, and cycle the boom slowly several times to warm the seals. The holding valves may respond more slowly in cold conditions; do not rely on them to hold load until the hydraulic system has reached operating temperature.

The Sany Cylinder Assy-Boom-Telescoping is also available as part of a complete telescoping boom overhaul kit, which includes both cylinders, all telescoping rope sets, guide wheel brackets, and telescoping cylinder seal kits. Sany recommends this complete‑kit approach for vehicles with over 8,000 operating hours, as it allows the entire telescoping system to be renewed in a single service event, eliminating the risk of hidden cylinder wear that could affect synchronization.

Fleet managers using this strategy report a 50% reduction in telescoping mechanism‑related failures and a 40% reduction in total boom system maintenance costs over the equipment’s life. Contact our parts specialists through the Get Quotation button above for custom kit configurations tailored to your fleet’s specific needs.