07018-21155 0701821155 RING,SEAL OF D475A-5E0 D475A-2

1. Quick Details of  seal 07018-21155:

2. 07018-21155 parts on group :

3.  07018-21155 picture:

4. Service part number :

5. FAQ

Q: Which medium bulldozer models use this piston seal ring 07018-21155, and what bidirectional hydraulic pressure sealing performance can this single split bronze piston seal realize inside the transmission clutch hydraulic piston chamber?
A: This OEM standard piston seal ring numbered 07018-21155 is exclusively matched for Komatsu D41 and D65 medium construction bulldozers, installed on the internal pressure piston of the main transmission clutch hydraulic chamber. The clutch piston bears continuous reciprocating compression strokes under long-term stable medium hydraulic pressure during medium open-pit mine moderate ore pushing, rural highway subgrade trimming and medium-volume construction residual soil stripping projects. It withstands frequent instantaneous pressure spikes triggered by uneven gravel and broken rock ground violent bumps, long-term continuous erosion of medium-temperature anti-wear transmission clutch hydraulic oil and tiny metal clutch friction plate grinding debris, plus year-round outdoor drastic cold-hot temperature alternations between low-temperature freezing winter construction sites and non-stop full-load high-temperature summer continuous operation. This split tin bronze alloy piston seal assembly integrates a precision machined bronze main sealing ring paired with a thin HNBR elastic backing liner, realizing stable bidirectional hydraulic oil pressure isolation inside the clutch piston cavity. It effectively blocks high-pressure clutch hydraulic oil from cross-leaking on both sides of the piston to avoid clutch slipping, delayed gear engagement and bulldozer walking traction attenuation; the unique single-side split opening design supports automatic radial shrinkage compensation to offset long-term piston groove abrasion, while the matched HNBR elastic liner maintains continuous outward supporting tension to fill tiny piston groove clearances and prevent bronze ring extrusion deformation under instantaneous peak pressure impact. All components adopt customized dimensional standards exclusive to D41/D65 clutch pistons and cannot be mixed and matched with seal rings of other bulldozer models, suitable for full transmission clutch disassembly maintenance at regional medium construction machinery repair shops and dedicated bulldozer after-sales service stations, greatly cutting unexpected long-term equipment downtime caused by internal clutch cross oil leakage.

Q: What exclusive metal-rubber composite sealing comprehensive advantages does this tin bronze alloy piston seal ring have compared with filled PTFE composite piston seals or single integral rubber piston seals used in aftermarket D41/D65 bulldozer transmission clutches?
A: The transmission clutch piston of D41 and D65 medium bulldozers reciprocates thousands of times every day under sustained 23–30Mpa medium hydraulic pressure, fully immersed in medium-temperature anti-wear clutch hydraulic oil mixed with hard metal friction plate grinding debris all year round, and exposed to construction sites with large temperature difference fluctuations between cold winter and hot summer. High-strength tin bronze alloy main sealing ring owns natural metal self-lubricating texture, ultra-high compressive hardness and outstanding anti-hard particle scratch performance that ordinary single NBR/PU rubber and carbon-filled PTFE composite materials cannot reach; uniform dense bronze metal forging structure will not produce surface swelling, softening or peeling after long-term continuous soaking in hydraulic oil below 128℃, and the split opening structure can automatically adjust the outer diameter to compensate piston groove abrasion after millions of reciprocating sliding cycles. The thin HNBR elastic backing liner retains stable elastic tightening tension at ambient temperature as low as -36℃, effectively avoiding gap loosening and internal cross oil leakage caused by bronze ring cold shrinkage in low-temperature winter construction environments. Compared with multi-piece three-layer PTFE composite piston seals, this bronze integrated split structure has fewer assembly accessories, simpler installation steps and lower assembly failure probability; compared with single integral rubber piston seals, it completely avoids permanent compression set deformation and rapid extrusion damage under long-duration stable clutch pressure loads. This targeted metal-rubber matched composite layered protection structure extends the overall effective service life of the piston seal by more than 89% compared with ordinary single rubber piston seals, and significantly reduces repeated maintenance labor hours and spare parts repeated procurement comprehensive costs for medium construction fleet operators.

Q: How can on-site professional medium bulldozer maintenance technicians rapidly distinguish each independent component of this 07018-21155 piston seal ring set via exclusive color difference, surface texture and structural shape feature differences?
A: The tin bronze alloy main piston sealing ring is uniform golden brass matte solid split metal ring with fine dense metal forging grain texture on the surface, smooth dry outer sliding surface without sticky rubber touch feeling, and adopts flat rectangular cross-section specially customized for clutch piston bidirectional hydraulic pressure sealing demands. The matched thin HNBR elastic backing liner is matte black thin strip soft rubber accessory with soft elastic touch, closely attached to the inner circular edge of the bronze ring to provide uniform radial outward supporting tension. The bronze ring has an obvious single-side split opening reserved for installation and automatic shrinkage compensation, which is the most intuitive structural feature to distinguish it from integral non-split sealing rings. Every bronze sealing ring is engraved with miniature micro laser engraved dimension and part number identification codes corresponding to D41/D65 clutch piston groove standard parameters, supporting one-to-one rapid sorting and accurate size matching during full clutch disassembly overhaul work. Inferior imitation thin copper seal rings have rough uneven surface texture, ultra-thin easy-to-bend metal wall thickness, fuzzy or missing laser marking codes, and lack matched HNBR elastic backing liners; inferior single rubber replacement seals have no metal main sealing ring, only integrated single black rubber one-piece structure without split opening design.

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