$23.$ Corrosion tests used with petroleum$-$based hydraulic fluids determine the effect on metal

parts of components from $\_\_\_\_\_\_\_\_$ compounds that have remained in the fluid after refining.

$24.$hich of the following is a general method used

to establish the lubrication and wear$-$prevention

qualities of hydraulic fluids?

A$.$ Capillary viscometer.

B$.$ Extreme$-$pressure test.

C$.$ Saybolt universal viscosity system.

D$.$ All of the above.

$25.$ When storing and handling replacement hydraulic fluid drums, place drums on their sides

to reduce chances of $\_\_\_\_\_\_\_\_\_\_\_\_$

$26.$cylinders are exposed to extreme

conditions, contamination of system fluid can be

reduced by usin

to prevent the entry of dirt

from the surfaces of the piston rods.

$27.$ Fluid samples taken from hydraulic systems for routine testing purposes should be collected only from the $\_\_\_\_\_\_\_\_\_\_\_\_$ of the fluid in the reservoir and only when the system is at operating temperature.

$28.\_\_\_\_\_\_\_\_\_\_\_$ in the fluid of a hydraulic system is caused by forcing fluid through the system without completing work outside of the system.

$29.\_\_\_\_\_\_\_\_\_\_\_$ than$-$recommended temperatures cause fluid oxidation and general fluid deterioration.

$30.$ The cleanliness of the fluid in most hydraulic systems is ensured by the addition of$\_\_\_\_\_\_\_\_\_$

A$.$ temperature control devices

B$.$ adequate storage drums

C$.$ filtration devices

D$.$ transfer pumps