Mercury MerCruiser Quicksilver Water Pump Washer 8M0005777
In stock items ship same or next day.
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Product Description
Mercury Quicksilver 12-8M0005777 is a washer used in specified outboard water-pump assemblies. It is listed in the pump/impeller component stack and is now superseded by 12-8M0204720.
Key Features
- Legacy OEM number: 12-8M0005777.
- Water-pump assembly washer.
- Two required in the referenced water-pump assembly.
Compatibility and Fitment
The Mercury 40 hp EFI Jet catalog for serial numbers 1C051324 through 1C453839, 1.83:1 driveshaft gear housing, identifies the washer at position 32. Confirm the installed pump and gearcase.
Replacement and Installation
Inspect both washers during water-pump service and replace damaged pieces. Refit them in the pump-diagram sequence with the correct impeller and key.
Alternate / Superseded Part Numbers
12-8M0005777 is superseded by 12-8M0204720.
Mercury Parts Finder
Search Mercury parts by serial number or part number.
Parts Desk Insight
The diagram can require two washers even though a replacement may be sold individually. Check the pump’s full parts list before reassembly.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.