Cummins/Onan 20W-20 — Fuel Transfer Pump Removal and Disassembly
Repair & overhaul
For the Cummins/Onan 20W-20, from the Cummins/Onan service manual.
Applies to: Cummins/Onan 20W-20, Cummins/Onan RDJF engine
Before you start
- Do not pry the cover and body apart; this would damage the diaphragm.
Procedure
- Remove pump inlet and outlet lines.
- Remove two cap screws holding pump to engine and lift off.
- Notch cover and body with a file; remove six screws.
- Tap body with a screwdriver to separate the two parts.
- 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.
Full service-parts list: Cummins/Onan 20W-20 →
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.