Power Steering Pump 21-394 Fit for Nissan/Infiniti - Reliable

Our review of the 21-394 power steering pump finds it best suited for owners of mid-2000s to late-2010s Nissan 370Z and a wide range of Infiniti EX, FX, G, M, Q and QX models who need a direct-fit replacement that restores hydraulic steering assist. The bottom line: this pump reproduces OE dimensions, is built from aluminum and iron for heat and corrosion resistance, and improves steering assist and comfort on long drives, making it a practical repair choice when the original pump fails.

Key Features

• Direct-fit compatibility: Replaces OE part numbers including 21-394 and 21-415 so it installs without major modification on listed Nissan and Infiniti models.
• Wide vehicle coverage: Fits many model years and series including 370Z, EX35/37, FX35/37, G35/37, M35/M37, Q40/Q50/Q60/Q70/Q70L and QX50/QX70 for straightforward cross-compatibility checks.
• Durable construction: Made from corrosion-resistant aluminum with iron components, designed to tolerate high under-hood temperatures and regular drivetrain stress.
• Restores steering effort: Returns power assist for smoother turning, improved stability and reduced driver fatigue on longer drives.
• Replacement for multiple OE codes: Covers several OEM references (18601492-101/102/103) to simplify part selection when matching old pump numbers.
• Warranty support: Includes a one-year warranty for added peace of mind after installation.

Who It's For

This pump is aimed at DIY mechanics and independent shops replacing a failed hydraulic power steering pump on compatible Nissan 370Z or Infiniti models. It is especially useful when a like-for-like, dimensionally correct unit is required to avoid re-routing hoses or modifying mounts.

Drivers who need perfect OEM-level noise control or who have vehicles with four-wheel steering should compare fitment carefully or consult a dealer, since several model exceptions are noted for 4WS-equipped cars and some specific drivetrains.

Pros & Cons

Pros

• Direct-fit design simplifies installation and reduces the need for extra parts.
• Solid aluminum and iron construction gives confidence in heat and corrosion resistance.
• Restores steering assist effectively, improving drivability and reducing fatigue.
• Good value for money compared with dealer-only replacement options.

Cons

• Some customers report elevated noise levels after installation, so expect variability compared with the original unit.
• Not compatible with certain 4-wheel steering models; verify fitment before purchase.

Specifications

Product Type	Power steering pump (power assist pump)
Compatible Models	Nissan 370Z and Infiniti EX, FX, G, M, Q, QX series (selected years)
Engine Fitment	V6 3.5L and 3.7L applications as listed
OE Part Numbers Replaced	21-394, 21-415, 21-416, 18601492-101/102/103
Materials	Corrosion-resistant aluminum with iron components
Warranty	One-year warranty

Our Verdict

The 21-394 power steering pump is a pragmatic, cost-effective replacement for owners of supported Nissan and Infiniti models who want a direct-fit unit that restores hydraulic assist and holds up under heat. It offers solid construction and broad compatibility, though potential buyers should check fitment carefully for 4-wheel steering exceptions and be aware that noise performance can vary between units.

Frequently Asked Questions

Will this pump fit my model year?
Check the detailed vehicle list for exact model years and engine sizes; it fits many 2007-2020 Nissan and Infiniti V6 3.5L and 3.7L models but verify before purchase.

Does it include a pulley and is it ready to install?
The product is listed as a power assist pump with pulley replace for related OE numbers, but confirm the package contents in the product listing and compare to your removed unit before installation.

What about noise after installation?
Most buyers report good function and fit, but some have noted noise; proper fluid level, bleeding and belt tension can reduce noise, and the one-year warranty covers manufacturing defects.