Coolant Reservoir Cap / Surge Tank Fill Cap – 572.2045 or 05-32313-000

A small component with a critical job. The rTech Black Label RT2045 Coolant Reservoir Fill Cap is a heavy-duty replacement designed for select commercial truck cooling systems. 

A properly fitting reservoir cap helps keep the cooling system sealed and helps prevent coolant loss at the reservoir opening during normal operation.

Built for demanding commercial service, the RT2045 provides a straightforward replacement for compatible coolant surge tank applications.

Built for uptime. Built for serious trucks.

Features & Benefits

• Heavy-duty coolant reservoir cap
• Designed for compatible surge tank fill locations
• Helps maintain a secure seal at the reservoir opening
• Helps reduce coolant loss from a worn or damaged cap
• Durable construction for commercial vehicle environments
• Straightforward threaded installation
• Designed as an aftermarket replacement for compatible applications
• Fleet-approved Black Label quality

rTech Product Specifications

• rTech Part Number: RT2045
• Product Type: Coolant Reservoir / Surge Tank Fill Cap
• Installation: Threaded
• Series: rTech Black Label

Pressure rating and thread specification should be verified against the actual RT2045 product before being published.

Vehicle Applications

Designed as an aftermarket replacement for select Freightliner coolant reservoir applications, including certain 2018-up Cascadia P4 reservoir configurations. The 572.2045 / 05-32313-000 interchange is catalogued for the reservoir top/fill location on these applications.

Cooling-system configurations can vary by chassis, model year, engine, and reservoir. Verify fitment by VIN or existing cap number before ordering.

Direct Cross References

• rTech Black Label: RT2045
• Automann: 572.2045
• Freightliner: 05-32313-000
• Freightliner: 0532313000

Cross-reference numbers and manufacturer names are provided for identification and fitment purposes only. All trademarks are the property of their respective owners. rTech Black Label products are independent aftermarket replacement parts and are not manufactured, sponsored, endorsed, or approved by the referenced manufacturers. Always verify fitment before installation.

Why the Correct Reservoir Cap Matters

A coolant reservoir cap is small, but it forms an important part of the cooling system.

A worn, damaged, loose, or incorrect cap can compromise the seal at the reservoir opening and contribute to coolant loss.

Replacing a damaged cap with the correct application helps support:

• Proper reservoir sealing
• Coolant retention
• Reliable cooling-system operation
• Reduced risk of leaks at the cap
• Consistent fleet maintenance

For commercial fleets, even inexpensive cooling-system components deserve attention.

Small part. Important job.