Cummins/Onan — Fuel Transfer Pump Removal and Disassembly
Repair & overhaul
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Do not pry the pump body and cover apart; this would damage the diaphragm.
Procedure
- Remove pump inlet and outlet lines.
- Remove two cap screws holding pump to engine and lift it off.
- Notch the pump cover and body with a file so they can be reassembled in same relative positions, then remove six screws.
- Tap the body with a screwdriver to separate the two parts; do not pry apart.
- Remove screws holding valve plate to cover and lift out valve and cage assemblies.
- Drive out rocker arm hinge pin.
- Remove rocker arm, spring and link.
- Lift out diaphragm assembly and diaphragm spring.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Cummins/Onan 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.