OVERVIEW
Genuine VW/Audi shouldered mounting nut, part number N-901-752-05. This original M6 hex nut secures the leak-detection pump bracket or specified cooling-fan attachment at the assigned positions on the configurations listed below. It is supplied individually for mounting hardware replacement during inspection or repair.
Technical details
- Original number: N-901-752-05 / N90175205.
- Published nominal thread size: M6.
- Hex wrenching flats with a broad shoulder beneath the nut body.
- Specified applications: leak-detection pump bracket and cooling-fan mounting hardware, as listed in the fitment table.
- One nut supplied. Pump, bracket, mounting stud, hoses, filter and other hardware are separate.
The shoulder provides the specified contact arrangement at the mounting point. Correct hardware retains the bracket in its assigned position so the pump and connected components remain supported. This nut does not form a hose connection or replace the fastener that attaches the pump itself to its bracket.
The same nominal M6 thread appears in many vehicle locations, but shoulder geometry and original part number still matter. Match N90175205 at the actual mounting point and inspect the separately specified stud or bolt before ordering.
Common reasons to replace
Replace damaged threads, rounded wrenching flats, deformation, missing hardware or corrosion affecting reliable installation. Replacement may also be appropriate after earlier repairs have left an incorrect substitute at the bracket mounting point.
Inspect the nut when the leak detection pump bracket is removed for diagnosis or component replacement. Follow any factory instruction to renew mounting hardware and check the mating stud or bolt for damage before fitting a new nut.
Loose or damaged bracket hardware should be corrected as part of restoring the original mounting arrangement. A new nut cannot repair a cracked bracket, damaged body mounting point, defective pump or broken hose connection.
Evaporative-emissions faults require system diagnosis. This mounting nut is a retaining component, so replacing it alone does not resolve an electrical pump fault, failed valve, leaking hose or defective emissions component. Repair the confirmed cause and ensure the mounting assembly is complete.
Installation and service notes
Follow the factory procedure for the exact vehicle's leak detection pump and mounting bracket. Identify the bracket-to-vehicle attachment before removing hardware, and support the assembly so attached hoses and wiring are not strained.
Inspect the bracket, mounting surface and mating threads. Correct damaged components and position the bracket normally before installing the nut. Start it by hand without cross-threading and make sure the shoulder seats at the prescribed contact point.
Use the correctly sized hex tool and the factory tightening requirement for this attachment. Do not transfer a torque from the pump-to-bracket screw, a parking brake cable bracket or another M6 fastener. Follow the specified thread preparation and hardware replacement instructions.
Do not tighten the nut to pull a distorted bracket into place. If the mounting connection binds or does not seat correctly, inspect the bracket alignment and original hardware selection before continuing.
After assembly, confirm the bracket is secure and connected hoses and wiring have their required routing and clearance. Complete the operating and diagnostic checks required by the component repair. This listing supplies one original nut; select other mounting and emissions-system components separately.
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 | Specified leak detection pump bracket-to-vehicle mounting nut. Confirm original N90175205 at this position; other pump fasteners differ. |
| Audi S4 Avant | 2001–2002 | 2.7L twin-turbocharged gasoline V6, APB | B5 wagon, quattro; 6-speed manual | Specified leak detection pump bracket-to-vehicle mounting nut. Confirm original N90175205 at this position; other pump fasteners differ. |
| Volkswagen R32 | 2004 | 3.2L gasoline VR6 | Mk4 hatchback, 4Motion; Six-speed manual | Specified original cooling-fan mounting nut. Match N90175205 at the assigned attachment; the fan, studs and other hardware are separate. This is a different mounting use from the S4 leak-detection pump bracket. |
Cooling-fan hardware service: On the listed R32, match this nut to the original fan mounting position. Replace damaged, corroded or missing nuts and inspect the stud and fan support. Follow the vehicle service procedure for isolating the fan before working near it; mounting hardware does not repair a failed fan motor or damaged fan blade.
Confirm original N90175205 and the leak detection pump bracket mounting position before ordering. One nut supplied.