Troubleshooting
11Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Oil leakage past spool seal into spool cap | If spool cap contains oil, replace spool seal o-ring. If o-ring retainer is “belled” check for restriction from “out” port reservoir. | See item 30. |
| Broken return springs | Replace springs. See item 30. | |
| Bent spool | Return for factory repair or replace with new spool section. See item 30. | |
| Foreign particles | Clean system and valve. | |
| Misalignment of control handle linkage or spool bonnet | Check linkage for binding condition; loosen bonnet, operate valve to realign, and retighten. | |
| Spool not moved to full stroke | Spool travel should be 5/16 | |
| Poppet in control valve not holding | Clean check poppet(s) carefully. Ensure free movement and proper seating or replace check poppet(s). See item 30. | |
| Damaged or worn spool seals | Replace spool end seals. | |
| Ball in anti-cavitation valve stuck or not seated properly | Clean anti-cavitation valve carefully. Assure that checks move freely and seat properly or replace cartridge. See item 30. | |
| Valve cap and center return mechanism binding | Loosen screws holding cap on valve (ref. Item#2 P.22). Operate valve spool and retighten screws. | |
| Valve malfunction due to dirt or packing material | Dirt and shreds of packing material are the usual causes of valve malfunction. Be sure that oil supply is kept clean. Use only factory supplied packings in cylinder repair. Fittings and hoses must be clean before being removed. |
Fault codes and symptom→remedy steps extracted from this unit’s service/owner documentation; verify against the official manual before servicing.
Available documents
Service manual
About
Allmand MODEL 75 — light tower. Specifications and parts compiled from manufacturer documents.