Cummins/Onan QST30 — Rupture Basin Leak Detect Switch Test
Maintenance
For the Cummins/Onan QST30, from the Cummins/Onan service manual.
Applies to: Cummins/Onan DFHA, Cummins/Onan DFHB, Cummins/Onan DFHC, Cummins/Onan DFHD, Cummins/Onan QST30, Cummins/Onan QST30 engine
Procedure
- Remove pipe fitting/switch assembly from rupture basin tank.
- Move O/Manual/Auto switch to MANUAL position.
- Activate leak detect switch (move float upward).
- Check control display for Rupture Basin fault message. Repair defective circuit if no fault.
- Apply thread sealant to pipe fitting and install switch assembly.
Tools required
- thread sealant Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan DFHA →, Cummins/Onan DFHB →, Cummins/Onan DFHC →, Cummins/Onan DFHD →, Cummins/Onan QST30 →
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.