HCYY11112004 Steering Cylinder for Aerial Work Vehicles

Compact but High-Pressure

The 20 MPa working pressure of the HCYY11112004 is the same as the much larger GTHZ210C boom steering cylinder (Φ63, 13 kg). The difference is in the force output: the Φ40 bore produces approximately 25.1 kN of extend force at 20 MPa, compared to 65.4 kN from the Φ63 bore. The smaller force is matched to the lighter weight of the AWV platform this cylinder serves — less machine weight on the steered axle means less force needed to turn the wheels.

30 MPa Maximum Withstand

The 1.5× proof ratio (30 MPa max ÷ 20 MPa working) ensures the cylinder housing and seals survive transient pressure spikes without damage. Steering circuits experience pressure spikes when the wheels hit obstructions (kerbs, debris, uneven ground) that suddenly resist the steering motion — the pressure surges momentarily as the hydraulic system absorbs the impact. The 30 MPa rating provides the margin for these dynamic events. Every HCYY11112004 is proof-tested at 30 MPa before shipment.

Is the HCYY11112004 the same as the HCYY11112007 or HCYY11112012?

No. All three are steering cylinders for aerial work vehicles, but they serve different AWV platforms with different dimensional specifications. The HCYY11112004 is Φ40×Φ20×125 at 20/30 MPa and 2.8 kg; the 007 and 012 variants have different dimensions for different platforms. Always order by the exact part number on the cylinder you are replacing.

The steering feels jerky at low speed — should I replace the steering cylinder?

Jerky low-speed steering (stick-slip) on aerial work vehicles is typically caused by rod seal hardening inside the steering cylinder — the seal friction exceeds the hydraulic driving force at very low flow rates, causing the rod to stick and then jump forward when enough pressure builds. A new HCYY11112004 with fresh, correctly specified seals eliminates this immediately. Before ordering, also check the steering linkage for worn ball joints or bent tie rods — mechanical backlash in the linkage can produce similar symptoms.

Can I order the HCYY11112004 with the HCYY11112003 lifting cylinder for a combined replacement?

Yes. Ordering multiple HCYY AWV cylinders together is recommended — all are manufactured on the same production line in the same batch, shipped in one package. The HCYY11112003 (lifting, 27 kg) and HCYY11112004 (steering, 2.8 kg) are the two most common replacement cylinders on scissor-type AWV platforms. Replacing both during a single service window eliminates the risk of a second downtime event when the remaining cylinder eventually fails.

What does the 30 MPa maximum withstand pressure mean for daily operation?

In daily operation, the steering circuit pressure should never reach 30 MPa — the system relief valve limits it to approximately 20 MPa. The 30 MPa rating is a proof-test margin for transient spikes (wheel impacts, debris, sudden load changes during steering). Every HCYY11112004 is tested at 30 MPa for a minimum of 2 minutes before shipment. If your steering circuit regularly reaches pressures above 20 MPa, the hydraulic system has a fault that should be diagnosed before it damages the cylinder. Contact Korea Ever-Power for a replacement quotation.

Replaced the steering cylinder on our scissor lift platform — the old one had developed stick-slip that was making positioning nearly impossible. The HCYY11112004 from Ever-Power fitted perfectly: Φ40 bore, 125 mm stroke, 400 mm pin centres all matched. Steering is smooth and precise again from the first use. At 2.8 kg the cylinder is light enough to install with one hand while threading the fittings with the other. Total swap time was about 30 minutes. Excellent quality for the price.

We ordered the HCYY11112004 steering cylinder and HCYY11112003 lifting cylinder together for a scheduled service. Both arrived in one package, 20 days from order to delivery. The steering cylinder is impressively compact — hard to believe 2.8 kg can handle 20 MPa. Both cylinders passed our pre-installation pressure test at 30 MPa (steering) and 27 MPa (lifting) without issues. Installed on the AWV platform, both are performing at OEM level. We've added these to our standard reorder list.

Good cylinder, correct fit. The only reason for 4 stars: we initially ordered the HCYY11112007 by mistake (wrong variant for our platform). Ever-Power processed the exchange quickly, but it cost us a week. Our lesson: always check the exact HCYY part number on the old cylinder before ordering. The HCYY11112004 itself works perfectly — smooth steering, no leaks after 4 months of daily construction-site use.

Third HCYY steering cylinder we've purchased from Ever-Power — this time the 004 for a different platform in our fleet. Consistent quality every time. The 30 MPa test certificate was included in the box, which our safety inspector requires. Simple transaction, correct product, fast delivery. That's all we need.