OVERVIEW
Genuine VW/Audi adjustable hose clamp, part number N-102-581-01. This original screw-type clamp retains a hose at its prescribed fitting. Confirmed applications include the B5 S4 auxiliary coolant pump hoses and the specified ALH Golf breather connection below. One clamp is supplied.
Technical details
- Original number: N-102-581-01 / N10258101.
- Published nominal clamping range: 23–35 mm.
- Published band dimensions: 9 mm width x 0.5 mm thickness.
- Adjustable worm-drive band with screw housing, as pictured.
- Hose, pump, breather components and other clamps are separate.
The screw mechanism adjusts the band around the hose at its fitting. The hose and connection must be correct for the vehicle's original arrangement. The clamp range does not establish that every hose within that diameter is a confirmed application.
This original number is used in different systems. The S4 application listed below is a coolant hose connection; the ALH Golf application is part of crankcase ventilation. Match the exact mounting position rather than transferring a service procedure between these two systems.
Common reasons to replace
Inspect the clamp when removing a hose or servicing the associated pump or breather connection. Replace a distorted band, damaged screw housing, stripped adjustment mechanism or corrosion that prevents secure installation. Follow any factory requirement to renew removed clamps.
A clamp that is incorrectly sized, twisted or positioned away from the retention area may not secure the hose normally. Check the hose and fitting as well as the clamp. Excess tightening cannot repair a split hose, hardened sealing area or damaged fitting.
Coolant loss, a breather leak or abnormal operation requires diagnosis of the affected system. A new clamp does not repair a failed coolant pump, cracked hose, damaged breather component or leak elsewhere. Correct the diagnosed condition before reassembly.
Installation and service notes
Use the factory procedure for the exact system and connection being serviced. For coolant hose work, allow the engine to cool and follow the prescribed draining steps before opening the connection. For breather service, keep contamination out of the opened hose and engine connection.
Identify the assigned clamp position and inspect the hose, fitting and retention area. Select the required hose or component separately if damage is found. Compare the original number, diameter range and band arrangement before fitting the new clamp.
Seat the hose fully and position the clamp as prescribed. Keep the band square to the hose and the screw housing clear of surrounding components. Do not use the clamp to force a mismatched hose onto a fitting or compensate for incorrect routing.
Use the correct tool for the adjustment screw and follow the connection-specific tightening requirement. Do not apply extra force to a stripped mechanism or tighten until the hose is visibly damaged. The required setting depends on the prescribed hose and fitting arrangement.
Where replacement hose assemblies or aftermarket components are fitted, confirm their verified hardware requirements. This original clamp does not establish compatibility with every replacement coolant or ventilation hose.
Complete the required system checks after assembly. Coolant service may require refilling, bleeding and leak checks; breather service requires confirmation of correct hose routing and a secure connection. One clamp is supplied, so order the quantity required for the positions being serviced.
Fitment
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi S4 | 2000–2002 | 2.7L twin-turbocharged gasoline V6, APB | B5 sedan, quattro; 6-speed manual | Original auxiliary coolant pump hose attachment requiring N10258101. This clamp is used at each of the pump's two hose connections; one clamp supplied. Confirm hose and pump arrangement. |
| Volkswagen Golf | 1999–2003 | 1.9L turbocharged direct-injection diesel, ALH only | Mk4 hatchback, front-wheel drive; Original factory arrangement | Mk4/ALH only. Specified crankcase breather hose clamp position requiring N10258101. Match actual hose and fitting; other breather connections can use different clamps. One clamp supplied. |
Confirm original N10258101 at the specified hose connection and use the service procedure for that system. One clamp supplied.