Hercules — Fuel Transfer Pump Testing
Testing & diagnosis · fuel system
From a Hercules service manual covering: D-1500, D-1700, D-2000, D-2300, D-3400, De3000. Check it applies to your exact model before use.
Applies to: Hercules D Series engine
Procedure
- Disconnect fuel line from fuel filter and install 3/8-18 NPTF tee in fuel filter base.
- Connect fuel line and pressure gauge to pipe tee.
- Start engine and run at approximately 1800 rpm.
- Gauge should register 3 to 4-1/2 psi.
- Replace fuel pump if pressure is less than 3 psi.
- If no gauge, disconnect fuel line at fuel filter, crank engine, and check forceful fuel flow.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Pressure 3 to 4-1/2 psi at approximately 1800 rpm; replace if less than 3 psi.
Source: Hercules service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.