QY55KA-Y Upper Telescopic Seal Kit S34 / S35
Upper boom stages use different cylinder geometry from the lower stage. S34 and S35 must be identified by exact stage and cylinder reference before seals are opened.
The Match That Matters
Upper boom stage S34 or S35
Cylinder assembly labels
Rod/bore measurements
Seal direction and wear rings
Telescoping sequence symptoms
Confirm whether one or both upper-stage cylinders are being repaired and keep their seal groups separate.
What the Symptom Really Tells You
Uneven boom sequencing is not automatically a seal problem; sequence valves, cable/chain systems and load-holding valves may influence movement.
Workshop Notes
Mark each cylinder and component, inspect straightness and surfaces, fit seals with sleeves and verify smooth sequential extension under controlled pressure.
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Buyer FAQ
Are S34 and S35 kits identical?
Do not assume; verify each stage.
What causes jerky extension?
Air, guides, valves or seals may contribute.
Can kits be mixed?
Keep each stage kit separately identified.
Packing: S34 and S35 groups are separated, labelled and kept flat.
