Allmand — Relief Valve Pressure Too High Diagnosis
Testing & diagnosis
From a Allmand service manual covering: M-250 Series, M-258, M-259, M-301, M-303, M-304, M-310, M-311, M-313, M-314, M-319, M-326…. Check it applies to your exact model before use.
Before you start
- Use a pressure gauge and consult manufacturer for proper pressure setting.
Procedure
- Symptom: amp draw and battery drain excessive when system is dead headed; motor RPM slow compared to full load.
- Turn relief valve adjusting screw counterclockwise using a gauge tee'd into high pressure line to record proper pressure setting.
- In style Fig 4 loosen jam nut; in style Fig 5 remove flush plug.
Tools required
- Pressure gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Allmand 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.