Cummins/Onan — Replacing Hydraulic Hose
Maintenance
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Running the pump without oil will quickly destroy it.
Procedure
- Consider that hoses shrink slightly in length and expand slightly in diameter under pressure.
- To avoid trapping air, slope hoses up from the pump and up to the reservoir.
- Do not bend hoses tighter than the hose manufacturer recommends.
- Make sure closed-loop lines are not reversed; color code them to match fittings.
- Flush hoses and cap them with JIC caps after cutting and terminating ends.
- Use wide-sweep 90-degree fittings.
- Support, restrain and protect hydraulic hose to prevent chaffing.
- Always use two wrenches when tightening fittings. Torque fittings per Table 1.
- Do not apply engine power to the pump before filling the pump and system with oil as instructed under STARTUP.
Tools required
- two wrenches Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- See Table 1 hydraulic fitting torques
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.