| |
Possible
Causes |
|
Remedy |
| 1 |
Partially clogged suction
line, intake filter/strainer,
or restricted intake pipe. |
1 |
Clean intake line, filter/strainer,
or eliminate restriction.
Ensure the suction line
is completely open. |
| 2 |
Air
leaks |
2 |
See
below: |
| |
| a. |
At pump intake piping
joints. |
| b. |
At
pump shaft packing
(if applicable) or
shaft seal. |
| c. |
Air
drawn in through the
suction pipe opening. |
| d. |
Around the pump casing. |
|
|
| a. |
Locate air leaks and
tighten joint required. |
| b. |
Replace pack or shaft
seal. Follow the manufacturer's
instructions. |
| c. |
Check fluid level
in the reservoir,
add fluid if necessary.
Ensure the pump inlet
is below the level
of the reservoir |
| d. |
Repair or replace
the pump/casing. |
|
| 3. |
Pump head too loose, or
a faulty head gasket. |
3. |
Replace the gasket and torque
the pump head bolts to the
correct specifications. |
| 4. |
Aeration
of fluid in reservoir |
4. |
See
below: |
| |
| a) |
Incorrect fluid |
| b)
|
Return line terminated
too high in reservoir |
| c)
|
Reservoir level low
causing excessive
heat and foaming. |
|
|
| a) |
Use a hydraulic fluid
that contains a foam
depressant. |
| b)
|
Terminate the return
lines below the fluid
level. |
| c)
|
Check the fluid level,
add fluid as necessary. |
|
| 5. |
Plugged
reservoir filter / breather
filler neck strain. |
5. |
Remove,
clean and replace. |
| 6. |
Fluid
viscosity too high. |
6. |
Drain
system and fill with fluid
recommended by manufacturer. |
| 7. |
Worn
or broken pump parts |
7. |
Replace
the worn or broken parts. |
| 8. |
Stuck
pump vanes (vane-type pump). |
8. |
Check
for burrs or solid contaminants.
If burrs, remove, clean
and/or replace parts as
necessary. If contamination,
flush system thoroughly
and filter fluid at refill. |
| 9. |
Improper
installation. |
9. |
See
below: |
| |
| a) |
Alignment. |
| b)
|
Rotation |
| c)
|
Pump RPM too high |
| d) |
Relief valve set too
low |
| e) |
Suction filter too
small. |
|
|
| a) |
Check alignment with
drive mechanism. Re-align
as necessary. |
| b)
|
Check for proper rotation. |
| c)
|
Check
the manufacturer's
descriptive bulletins
for the recommended
maximum speed. |
| d) |
Test and adjust the
relief valve as necessary. |
| e) |
Filter
capacity may be adequate
only when just cleaned,
replace with filter
of higher capacity.
|
|
///........
