Mercury MerCruiser Quicksilver Trim Pump Reservoir Screw with O-Ring & Spacer 18527
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Overview
Part Number: 18527 (service format: 10-18527)
Brand: Mercury / Quicksilver
Official Product Type: Screw with O-Ring and Spacer
Supersedes: 17648
GTIN: 745061123892
System: Power Trim / Tilt Pump-Motor Assembly — Bottom-Mounted Reservoir (Design I – 14336A8)
The Mercury Quicksilver 18527 is a genuine OEM screw with O-ring and spacer for the power trim / tilt pump-motor assembly on MerCruiser sterndrives equipped with the bottom-mounted reservoir, Design I (assembly 14336A8). It seals the trim pump reservoir and should be renewed during pump service rather than reusing worn sealing hardware. The key match for this part is the pump design and reservoir layout — not just screw size — since similar trim pump hardware can look nearly identical across different pump versions.
Key Features
- Genuine Mercury Marine / Quicksilver OEM replacement
- Screw, O-ring, and spacer supplied together
- Designed for the Design I bottom-mounted reservoir trim pump assembly (14336A8)
- Supersedes earlier Mercury part number 17648
- GTIN: 745061123892
Compatible Applications
- MerCruiser Alpha One Gen II sterndrive
- MerCruiser R / MR / Alpha One sterndrive
- MerCruiser Bravo One sterndrive
- MerCruiser Bravo Two sterndrive
- MerCruiser Bravo Three sterndrive
- MerCruiser Blackhawk sterndrive
- MerCruiser TR / TRS sterndrive
- MerCruiser Bravo XR / XZ sterndrive
- MerCruiser integrated transom applications
- MerCruiser race sterndrive applications including Scorpion 377, 500 EFI, 500 Carb (502), 500 Bulldog, and 575 SCi
- All applications where the parts diagram specifies the Design I bottom-mounted reservoir assembly (14336A8)
Serial Number Fitment Notice
Verify fitment by exact drive model, serial number, and the trim pump / motor reservoir parts diagram before ordering. The critical match is the Design I bottom-mounted reservoir pump assembly — Mercury produced multiple trim pump designs, and reservoir hardware is not interchangeable between pump versions even when components appear similar.
Dimensions & Weight
- Weight: Approx. 0.02 lb (0.009 kg)
- Packed dimensions: Approx. 3.8 cm × 3.8 cm × 2.5 cm (1.50 × 1.50 × 1.00 in)
When to Replace
Replace this screw assembly when the reservoir screw, O-ring, or spacer is damaged, leaking, corroded, or no longer seals the trim pump reservoir correctly. Best practice during any trim pump service or reservoir removal is to renew this hardware rather than reusing the original O-ring and spacer.
Installation Notes
- Confirm the correct pump/motor assembly design (Design I, 14336A8) before ordering
- Associated components in the Design I reservoir assembly include: oil reservoir cap 861597 / 18526, reservoir 18525A1, O-ring 25-17645, and pump assembly 18529
- Inspect all reservoir sealing hardware while the pump is open — replacing related O-rings and seals at the same time avoids a repeat service
- Torque the reservoir screw to the Mercury-specified value for the applicable pump assembly
- Check for trim fluid leaks after reassembly and before returning the vessel to service
Superseded / Alternate Part Numbers
- Current: 18527 / 10-18527
- Supersedes: 17648
Technical FAQ
Q: Does this part include the O-ring and spacer, or just the screw?
A: The 18527 is supplied as a complete assembly — screw, O-ring, and spacer are included together. Replace all three components as a set during service.
Q: How do I confirm this fits my trim pump?
A: Locate your drive model and serial number, then reference the Mercury MerCruiser parts diagram for the trim pump / motor assembly. Confirm the diagram shows the Design I bottom-mounted reservoir (14336A8). The reservoir screw on that diagram should reference 18527 or its service number 10-18527.
Q: Can I reuse the original O-ring when reinstalling the reservoir screw?
A: No. The O-ring should be replaced at every service. Reusing a compressed or aged O-ring risks a trim fluid leak at the reservoir. The 18527 kit includes a fresh O-ring for this reason.
Parts Desk Insight
This is a small but easy part to overlook during a trim pump service. The most common issue is customers ordering the wrong reservoir hardware because multiple Mercury trim pump designs look similar from the outside. Confirming the Design I designation (14336A8) on the parts diagram before ordering prevents the most typical mix-up. At pump service time, renewing the reservoir screw assembly along with any other exposed O-rings is straightforward and inexpensive compared to dealing with a post-service trim fluid leak.
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.