The Honda 78105-YB8-003 Volute Case is a genuine OEM replacement designed for WT20 and WT30 water pumps. Sourced directly from Honda, this component carries the same specifications as the part originally installed at the factory, ensuring it seats and seals correctly in your pump housing. Confirm your pump's serial number against the fitment table before ordering.
Key Features
- OEM Volute Geometry — the spiral chamber profile is held to Honda's original dimensions, preserving the hydraulic efficiency that determines flow rate and discharge pressure on the WT20 and WT30
- Direct-Replacement Fit — this genuine Honda part installs into the pump housing using the original bolt pattern and mating surfaces, with no reworking of ports or flanges
- Fitment — covers WT20 and WT30 Honda water pumps; verify your serial number against the compatibility table to confirm the correct production range
- Restored Pumping Performance — a cracked, eroded, or worn volute bleeds pressure and reduces flow; replacing it with this part brings output back to the pump's rated capacity
The volute case is the snail-shaped housing that surrounds the impeller in a centrifugal water pump. As the impeller spins, the volute's gradually widening spiral channel converts the high-velocity water coming off the impeller blades into usable pressure at the discharge port — the tighter the volute profile matches the original design, the more efficiently that energy conversion happens. When the volute cracks, erodes from abrasive or debris-laden water, or develops a poor seal at the mating face, the pump loses pressure and volume, and the engine labors harder to deliver less output. Replacing the volute case with part number 78105-YB8-003 restores the housing to its original internal geometry and gets the WT20 or WT30 back to rated performance.
Part Details
| Part Number | 78105-YB8-003 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Volute Case |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Water Pump | WT20, WT30 | All |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
