BOOM CYLINDER SEAL KIT

While the Arm Seal Kit handles the digging and pulling forces, the Boom Seal Kit is the "heavy lifter." The boom cylinders are responsible for raising and lowering the entire weight of the attachment, the arm, and the load in the bucket.

Because the boom cylinders often work in pairs and hold the most "static weight," their seal kits are engineered differently to prevent the machine from "creeping" or dropping dangerously while holding a load.

A standard boom seal kit contains specific rings designed for high-load, vertical stability:

• Main Rod Seals: High-modulus polyurethane to withstand the weight of the boom.

• Buffer Seals: Crucial for the boom, as it faces massive pressure spikes when the bucket hits the ground or a rock.

• Piston Seals (Double Acting): Heavy-duty rings that ensure no oil bypasses the piston, which would cause the boom to "drift" down during operation.

• Double-Lip Wipers: Designed to keep dust out, as boom rods are often extended for long periods in dusty environments.

• Phenolic Wear Rings: Extra-wide to support the side-loading that occurs when an excavator is sitting on uneven ground.

• Anti-Drift Technology: Boom seals must have a near-zero leakage rate. If the piston seal has even a microscopic bypass, the boom will slowly sink, which is a major safety violation on most job sites.

• Cushioning Seals: Many boom cylinders have internal "cushions" to slow the rod down at the end of its stroke. The seal kit often includes small specialized O-rings or seals for these cushion plungers.

• Heat Resistance: Since the boom stays under constant load (even when not moving), the oil in the boom circuit can get hotter than in other circuits. Premium kits use Viton or H-PU to handle this thermal stress.