Overview

The Attwood Marine AK5505-7 is a service kit for S500 and S800 bilge pumps, with outlet sizes in 3/4" (19 mm) and 1" (25 mm), and compatibility with Tsunami Bilge Mk2 setups. It covers the discharge-side service parts that commonly need replacement, including a 90-degree outlet, a straight outlet, a washer, and a non-return/check valve.

This kit makes sense when an existing pump is still in place and the job is focused on refreshing the outlet hardware rather than replacing the whole pump. On boats where bilge access is tight, having both a straight outlet and a 90-degree outlet in the same kit helps when the hose run needs to stay direct or turn immediately to clear nearby structure or equipment.

Key features

• Fits Attwood S500 and S800 bilge pump service applications and is compatible with Tsunami Bilge Mk2
• Includes both straight and 90-degree outlet fittings for different hose routing layouts
• Covers 3/4" (19 mm) and 1" (25 mm) outlet sizing used on these pump installations
• Adds a replacement washer and non-return/check valve for outlet-side service work
• Useful when the goal is to keep an existing pump installation in service without sourcing each outlet part separately

Compatibility and fit

This service kit is for the S500 and S800 pump size range, not the larger S1200 size. Before ordering, check the pump model on the housing and confirm whether the discharge hose on the boat is 3/4" or 1".

It is a good match for owners maintaining an existing bilge pump installation on a runabout, center console, fishing boat, or small cruiser where the pump is still sound but the outlet pieces or check valve need attention.

Installation and setup

Match the outlet style to the way the hose leaves the pump. The 90-degree outlet is useful when the discharge hose needs to turn right away above the pump, while the straight outlet suits runs with a more direct path.

When servicing the pump, inspect the sealing surfaces and the discharge hose at the same time. In a bilge compartment, it is much easier to replace worn outlet-side parts while everything is already apart than to reopen the area later for a small leak or a sticking check valve.

What's included

• 90-degree outlet
• Straight outlet
• Washer
• Non-return/check valve