We normally add ATF fluid half hyraulic, half ATF. Seems to work great.
Pressure by the hydraulic pump is made​​.
The "Pour Point" of engine oil is about -44ºF.
Under normal conditions no because the hydraulic fluid is usually oil based. In conditions that are not normal like space or lab conditions that are beyond normal temperature yes there could be a chance, but very unlikely.
The cross reference for m-4864 which is a hydraulic oil or transmission fluid is SAE 80 for below freezing temperatures. B (SAE 90) is used for temperatures that are above freezing.
The function of hydraulic lines is to connect to the hydraulic system to carry either water, oil or any other form of liquid for that system. The hydraulic line is extremely important to the function of the system and works based on either a low or high pressure.
Good Question . Next please.....
Air in the lines
galvanised pipe
galvanised pipe
Hydraulic is used in terms to define liquid. Hydraulic mining in the ole days was used by high pressure water. Hydraulic lines contain oil for cranes, booms, etc.
To keep the hydraulic fluid in (double acting cylinders) and to keep dirt/washwater/etc out.
Check for kinked hydraulic lines (hoses or pipes)Bleed all lines and cylinders of trapped air.Check hydraulic oil level.Change hydraulic filter.Have oil pump rebuilt, or replaced with new.