Hydraulic Fluid Requirements

Question 1

Hydraulic fluid requirements

Answer 1

Low viscosity to allow it to flow freely

Resistance to foaming or creating sludge

Good lubrication

Corrosion resistance

Resistance to heat and thermal stability across the temperature range

High boiling point and low freezing point (+80°c to -70°c)

Chemically inert

Non flammable with a flash point above 100°c

Good storage properties

Question 2

Hydraulic fluid available in two common forms

Answer 2

Synthetic and mineral

Important that the different types are not mixed because this will seriously affect the operation of the system

Contaminated fluids destroy seals and corrode components

Question 3

Synthetic

Answer 3

Fire resistant and doesn’t support combustion

Used in systems which have butyl rubber or Teflon seals

E.g. Skydrol

Question 4

Mineral

Answer 4

Used only in systems which have synthetic rubber seals and hoses

Suitable for high pressure systems

E.g. DTD 585 coloured red