Cummins/Onan — Installing the Hydraulic Pump
Installation
From a Cummins/Onan service manual covering: 5.5 HGJAA, 5.5 HGJAB, 5.5 HGJAC, 5.5 HGJAD, 5.5 HGJAE, 5.5 HGJAF, 6.5 HGJAA, 6.5 HGJAB, 6.5 HGJAC, 6.5 HGJAE, 6.5 HGJAF, 7.0 HGJAA…. Check it applies to your exact model before use.
Applies to: Cummins/Onan 5.5 HGJAD, Cummins/Onan 5.5 HGJAE, Cummins/Onan 6.5 HGJAE
Before you start
- Running the genset without oil in the hydraulic pump will destroy the pump.
- The high pressure spray from a leak or fitting in a hydraulic line can penetrate the skin, leading to possible blood poisoning.
Procedure
- Apply molybdenum disulfide paste or equivalent to the shaft spline.
- Torque the two flange screws to 20 lb-ft (26 N-m).
- Do not start the genset before the pump is connected and filled with oil.
Tools required
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Flange screws 20 lb-ft (26 N-m)
Full service-parts list: Cummins/Onan 5.5 HGJAD →, Cummins/Onan 5.5 HGJAE →, Cummins/Onan 6.5 HGJAE →
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.