Apollo 4604112083 Cylinder Seal Assembly AB600TP2 Screed Hydraulic Sealing for S1800-2 Asphalt Paver

Part 4604112083 is the cylinder sealing element used in the AB600TP2 screed assembly fitted to the Apollo S1800-2 asphalt paver. It sits inside the hydraulic cylinder that moves the screed, where it separates pressurised oil from the outside environment and keeps the rod running on an oil film rather than metal to metal. When this seal goes, the first sign is rarely a dramatic failure: it is a thin film of oil on the rod, then oil on the screed frame, and finally a cylinder that creeps down when the machine is parked.

• Oil weep on the rod: a visible wet line or dust ring collecting oil at the gland. Early stage, still cheap to fix.
• Screed creep: the screed loses height when the paver stands still, so the first metre of every joint comes out thin.
• Uneven extension: one side of the screed extends slower than the other, and the crew compensates with the slope control.
• Pressure loss under load: the cylinder holds position when empty but sags when paving at full width.
• Seal hardening: on dismantling, the lip is hard, cracked or flattened instead of flexible, typical of heat and age rather than contamination alone.

Two or more of these together justify opening the cylinder rather than topping up oil. Replacing the sealing element early avoids scoring the rod and the bore, which turns a seal job into a cylinder replacement.

• Application-specific geometry: the profile is cut for the AB600TP2 cylinder gland, so the lip preload and groove fit match the original part.
• Correct compound for paving heat: the seal material is chosen for the temperature range a screed cylinder sees, not for general hydraulic use.
• Oil retention with low friction: the lip keeps pressure inside while allowing the rod to move without stick-slip, which matters for fine screed height changes.
• Direct replacement: no machining, no adapter, no change to the cylinder assembly procedure.
• Single-piece supply: ordered as an individual part, which suits workshops that stock by failure rate rather than by kit.

Clean the gland and rod before fitting. Lubricate the new seal with the system oil rather than grease, seat it square in the groove, and check that the lip faces the pressure side. After reassembly, cycle the cylinder through its full stroke several times before paving and inspect the rod for weeping after the first hour of work. If oil returns immediately, check rod straightness and bore scoring before replacing the seal a second time.