Volvo Penta Expansion Tank Pressure Cap | 23321023
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Part Number: 23321023
Brand: Volvo Penta
Official Product Type: Pressure Cap — Cooling System Expansion Tank
The Volvo Penta 23321023 is a genuine OEM pressure cap designed for the expansion tank in select Volvo Penta D6-series diesel cooling systems. It maintains correct system pressure, protects the heat exchanger and associated cooling components, and is a straightforward service item whenever the expansion tank or cooling circuit is being inspected or overhauled.
Compatible Applications
- Volvo Penta D6-280A-A (confirmed schematic reference — Cooling System / Expansion Tank assembly, diagram position 18)
- Additional D6-series variants may apply — verify against your engine serial number and the correct Volvo Penta cooling-system diagram before ordering
Serial Number & Fitment Notice
Cooling-system pressure caps can vary by engine family, tank design, and production break even when surrounding components look similar. Always match part number 23321023 to your engine serial number and the applicable Volvo Penta cooling-system exploded view before ordering.
System & Diagram Position
System: Freshwater / Closed Cooling — Expansion Tank
Diagram Position: Object 18 (D6-280A-A Cooling System schematic)
When to Replace
- Seal is worn, cracked, or no longer seating properly
- Spring tension is weak and cap fails to hold rated pressure
- Visible corrosion, damage, or coolant weeping around the expansion tank neck
- Any time the expansion tank or adjacent cooling components are being serviced — replacing the cap at the same time is low-cost insurance
Service Interval
Inspect at every cooling-system service. Replace immediately if the cap fails a pressure test or shows physical damage. Volvo Penta recommends pressure-testing the cap as part of routine freshwater cooling maintenance.
Installation Notes
- Confirm the correct schematic and serial-number fitment before installation
- Compare the removed cap against the replacement — verify pressure rating and tank-neck diameter match
- Inspect the expansion-tank neck and sealing surface; a damaged seat will cause the new cap to leak regardless of cap condition
Part Number & Supersession
OEM Part Number: 23321023
Supersedes: No confirmed supersession on record at time of listing
Replaced By: No confirmed replacement number on record — verify current status with Volvo Penta parts if ordering for a critical application
Dimensions & Weight
Compact pressure cap. Approximate shipping weight: 0.05 kg (0.11 lb). Exact installed dimensions vary by tank-neck specification — confirm fitment via schematic before ordering.
Kit Contents
Single pressure cap (23321023). No additional hardware included.
Related Parts
Commonly serviced alongside this cap:
- Expansion tank assembly (D6 cooling system)
- Heat exchanger and fuel cooler hoses and clamps
- Coolant — Volvo Penta genuine coolant recommended
Parts Desk Insights
Best use case: Routine cooling-system maintenance or any time the expansion tank is removed or inspected. This is a low-cost part that is easy to overlook — replacing it proactively during a cooling-system overhaul is good practice and avoids a return visit for a weeping cap.
Common customer issue: Customers sometimes order a pressure cap based on appearance alone. Caps that look identical can have different pressure ratings or tank-neck diameters. Always cross-reference the part number to your engine serial number and the D6 cooling-system diagram to confirm the correct cap for your specific expansion tank.
Technical FAQ
Q: Will this cap fit my D6-300 or D6-370?
A: The confirmed schematic reference is D6-280A-A. Other D6 variants may share this cap — verify against your serial number and the applicable Volvo Penta diagram.
Q: How do I know if my pressure cap is failing?
A: Signs include coolant loss without visible leaks, overheating, coolant weeping around the tank neck, or a cap that collapses under light hand pressure. A pressure tester will confirm cap performance.
Q: Is this a genuine OEM part?
A: Yes. Part number 23321023 is a genuine Volvo Penta OEM component.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.