Lafayette 3606 Engine VTJ5500 - Caterpillar

Hydraulic Tank
Illustration 1 g03650395
Hydraulic oil tank and filters
(1) Hydraulic oil tank
(2) Breathers
(3) Cap
(4) Vacuum sensor
(5) Return filters
(6) Oil level sending unit
(7) Case drain filter for swing and fan drive
(8) Case drain filter for main pump
(9) Case drain filter for travel and generator
(10) Sight gauge - oil levelThree case drain return filters (7) ( 8) ( 9) are mounted on the side of the hydraulic tank. Pump and motor case drain oil passes through one of these filter elements before entering the hydraulic tank.Two return filters (5) are on top of the hydraulic oil tank. Return oil passes through element of the return filters and flows into tank chamber.The air breathers are mounted on the top of the hydraulic oil tank. The air breathers maintain a certain air pressure in the hydraulic tank regardless of the following circumstances:
Change of air pressure in the hydraulic tank due to cylinder movement.
Change of air pressure in the hydraulic tank capacity due to a temperature change.Vacuum sensor (4) monitors the condition of breathers (2).Filters
The return filter elements are installed in housings that are inside the hydraulic tank. Oil flows from the anti-cavitation manifolds to the return filters. Clean hydraulic oil leaves the filter elements through the diffuser below the oil level in the hydraulic tank. The diffuser is positioned to prevent the formation of foam in the oil.If the filter element becomes full of debris, the flow restriction causes a pressure increase inside the filter. The pressure oil causes the bypass valve to open. The oil will then bypass the elements and flow directly into the hydraulic tank.The hydraulic tank has three separate case drain filters attached for the following systems:
Main pump
Swing system
Travel motor and generator (if equipped)