PPNZQAUT Windshield Washer Reservoir Assembly for Peterbilt 357/375/377/379 (1989–2007) — Heavy-Duty Tank with Pump & Cap

A complete aftermarket windshield washer reservoir assembly — tank, pump and cap — engineered to replace the original 603-5404/R86-6001 unit on compatible Peterbilt trucks.

This replacement washer fluid tank is built for heavy-duty use and designed to match the form and function of the factory item on select Peterbilt models from 1989–2007. It arrives as a fully integrated assembly with the electric pump and filler cap installed, so you can restore washer performance without sourcing multiple parts. The reservoir is molded from durable plastic to resist vibration and road conditions common to commercial trucks.

How will this reservoir restore my truck’s windshield washer function?

Installing this reservoir replaces worn, leaking, or cracked tanks and returns fluid delivery to the washer nozzles. The included pump reconnects to your vehicle’s existing wiring and hoses to re-establish proper flow and spray when the control is activated.

• Comes complete with electric washer pump and threaded cap for a ready-to-install assembly.
• Restores fluid containment and eliminates leaks that drain washer fluid.
• Matches mounting points and hose locations for direct-fit replacement on listed models.

Will this part fit my Peterbilt model and what part numbers should I check?

This aftermarket reservoir is produced to replace part numbers 603-5404, 6035404 and R86-6001, and is intended for specific Peterbilt trucks. Always confirm fitment with your truck’s year, make and model before ordering to ensure compatibility for your application.

• Designed to fit: Peterbilt 357 (1989–2007), 375 (1989–1999), 377 (1989–2007), 379 (1989–2007).
• Cross-references: 603-5404 / 6035404 / R86-6001 — aftermarket replacement, not OEM.
• Use your vehicle’s VIN or fitment tool to verify exact compatibility.

What should I expect during installation and can I do it myself?

Installation follows standard steps: remove surrounding trim or components to access the tank, disconnect hoses and the pump wiring, remove old unit, and mount the replacement tank. While a knowledgeable DIYer can complete this repair, professional installation is recommended for trucks with restricted access or complex wiring.

• Typical steps: disconnect battery, drain and remove old tank, transfer or connect hoses and electrical plug, secure new reservoir to mounts.
• Requires basic hand tools and possibly vehicle-specific trim removal tools.
• Professional service advised if mounting brackets or access panels complicate removal.

How durable is this aftermarket reservoir for heavy-duty use?

The reservoir is manufactured from reinforced plastic designed to withstand vibration, temperature changes, and exposure to washer fluids common in commercial use. It is tested to meet fit and performance expectations for the specified Peterbilt models, giving reliable service under typical fleet conditions.

• Material resists cracking from road vibration and thermal cycling.
• Sealed cap and pump assembly reduce leak points and contamination risks.
• Meant for long-term replacement of a failed or aged factory tank.

Who is this for: This PPNZQAUT 603-5404 washer reservoir assembly is aimed at fleet owners, owner-operators and maintenance technicians who need a direct-fit, economical replacement for worn or damaged washer tanks on compatible Peterbilt 357, 375, 377 and 379 models. If you require a complete tank with pump and cap to restore windshield washer performance quickly and cost-effectively, this assembly is a practical aftermarket option. Verify year/make/model fitment before purchase and consider professional installation if access is limited.