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5.4 Hydraulic fluids
The Hägglunds hydraulic system is primarily designed for operation with hydraulic
fluids according to ISO 11158 HM.
Fluids by the standards given in Table 4: Suggested fluid types are suggested.
Before the start of project planning, see data sheet RE 15414, Hydraulic fluid
quick reference, for detailed information on hydraulic fluids and specific additional
demands
Table 4: Suggested fluid types
So 11158
HM
HV
Details regarding the selection of hydraulic fluid
The hydraulic fluid should be selected such that the operating viscosity in the
temperature range, as measured in the motor housing, is within optimum operation
range, see Fig. 3: Selection diagram for viscosity ranges with straight fluids, i.e.
viscosity index 100. General recommendation is to have a system temperature of
50°C, see dotted line in Fig. 3: Selection diagram for viscosity ranges with straight
fluids, i.e. viscosity index 100. A VG 68 fluid will render just above 40 cSt at this
point.
• Optimum viscosity range is 40 to 150 cSt.
• Running above 150 cSt or below 40 cSt results in reduced efficiency.
• Running above 400 cSt results in substantial efficiency loss.
• For pumps, the maximum start-up viscosity is 1600 cSt.
• Running below 30cSt may impact the system service life.
• Running below 20 cSt may render instant system seizure.
Hägglunds DOb, RE 15327-WA/05.2017, Installation and maintenance manual, Bosch Rexroth AB
ISo 15380
HEES
HEPG
HEPR
Delivery contents
17/80
ISo 12922
HFB
HFC
HFDU
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