LAWSON ENGINEERS LTD Ref : PJ1682
Issue Date : 06.06.2006
4. When refilling or topping-up the hydraulic reservoir, clean around the filler cap and
pourer spout on the oil drum.
5. Oil whose purity is suspect must not be used.
6. Make sure that your hands or gloves remain free from grit, do not rub them on rags that
could leave a deposit of lint.
7. Do not take for granted that new hydraulic components are clean. Before fitting, they
should be examined visually, blown through with compressed air and, if possible, washed
in clean spirit.
b)
POSSIBLE CAUSES OF HYDRAULIC FAILURE.
1. Oil viscosity too high -ensure that correct grade of oil is used for ambient temperatures
encountered.
2. Foreign bodies trapped in return lines from control to tank.
3. Disintegrated oil seal in return lines from control to tank.
4. Failure of flexible return pipe inner lining.
5. Control valve spool scored or partially seized and not fully returning to neutral.
6. Control valve spool retarded by dirt or disintegrated oil seal.
7. Broken control return spring.
8. Hydraulic tank filter blocked.
c) POSSIBLE
CAUSES
OF
FULL PRESSURE FAILURE.
1. Pump drawing air.
2. Pump inlet choked.
3. Pump severely worn.
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