Hoist Circuit Filters - Komatsu 830E Shop Manual

HYDRAULIC TANK BREATHERS
There are two breather filters (3, Figure 3-16) located
on top of the hydraulic tank to allow air in and out of
the tank. The filters should be replaced at the interval
specified on the lubrication chart.
Keep the area around the breather filters clean and
free of debris build up. If there is any sign that the
breather filters are oil soaked, replace the filters as
soon as possible and check for proper oil level. Once
the breather filters become oil soaked, they will plug
very quickly.
NOTE: Plugged breather filters can cause pressure
build up inside the hydraulic tank and can cause the
service brakes to drag.

HOIST CIRCUIT FILTERS

Two hoist circuit filters (Figure 3-18) are located on
the fuel tank below the right frame rail. The filters pro-
vide secondary filtering protection for hydraulic oil
flowing to the hoist valve and hoist circuit compo-
nents.
An indicator switch (5) is designed to alert the opera-
tor of filter restriction before actual bypass occurs.
The switch contacts close at 35 psi (241 kPa) to actu-
ate a warning lamp on the overhead display panel.
Actual filter bypass occurs at 50 psi (345 kPa).
NOTE: When the engine is initially started and the
hydraulic oil is cold, the warning lamp may actuate.
Allow the hydraulic system oil to reach operating
temperature before using the warning lamp as an
indicator to change the element.
Refer to Section P, "Lubrication and Service" for rec-
ommended normal filter element replacement inter-
val. Earlier replacement may be required if the
restriction indicator lamp turns on.
Premature filter restriction may indicate a system
component failure and signal a service requirement
before extensive secondary damage can occur.
NOTE: An early indication of the filter warning light at
first installation may be due to restriction in the filter
as it cleans the system. Unless the fluid appears
contaminated or has a strong foul odor, do not
change the oil; replace only the filter element.
L3-14
FIGURE 3-18. HOIST CIRCUIT FILTER ASSEMBLY
1. O-Ring
2. Plug
3. Filter Head
4. O-Ring
5. Indicator Switch
6. O-Ring
7. Backup Ring
Hydraulic Component Repair
8. Setscrew
9. Filter Element
10. Bowl
11. Bleed Plug
12. O-Ring
13. Bottom Plug
7/02 L03026