721-98-05990 7219805990 Excavator Bucket Hydraulic Cylinder Complete Seal Kit Construction Machinery Replacement Parts

1. Quick Details of  seal 721-98-05990:

2. 721-98-05990 picture:

3. Service part number :

4. FAQ

Q: Can this cylinder seal kit fit hydraulic cylinders of all construction machines?
A: It is specially matched for excavator bucket cylinders. It cannot be used for grader lift cylinders or wheel loader steering cylinders with different installation dimensions.

Q: What kinds of working conditions suit this set of sealing components?
A: It performs steadily in quarry excavation and river dredging projects, adapting to frequent digging action and muddy, grit-filled operating environments.

Q: What temperature range can this whole seal kit withstand steadily?
A: It maintains reliable sealing performance within -59°C ~ 124°C under long-hour continuous heavy-load excavation work.

Q: Which details should maintenance staff focus on during cylinder overhaul and installation?
A: Clean all residues inside the cylinder groove thoroughly, and avoid sharp edges scratching the surface of every sealing part during assembly.

Q: What failures can this cylinder seal kit effectively avoid after installation?
A: It prevents internal and external hydraulic oil leakage, and reduces seal abrasion caused by frequent reciprocating movement of the bucket cylinder.

Q: What advantages does walnut fiber reinforced HNBR have compared with ordinary rubber?
A: It has excellent hydraulic medium resistance and dynamic fatigue resistance, suitable for high-frequency stretching movements of bucket cylinders.

Q: What sustained hydraulic pressure can this matched sealing assembly withstand during repeated cyclic operation?
A: Assisted by wear strips and back-up rings, the sealing system can continuously bear pressure between 5.25MPa and 6.05MPa and ease pressure fluctuations when lifting heavy bulk materials.

Q: What kinds of work sites usually require this lift cylinder seal kit for routine maintenance?
A: It is widely applied for servicing loaders operating in quarries, cement mixing stations, port freight yards and construction waste recycling bases.

Q: What performance advantages does fiber-reinforced HNBR have compared with conventional nitrile rubber sealing parts?
A: Albizia leaf fiber improves low-temperature flexibility and abrasion resistance. Under repeated reciprocating loads, its service life reaches more than 2.72 times that of ordinary NBR seals.

5. Exhibition and Wearhous

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