Hydraulics Final

The difference between an unbalance vane pump and a balanced vane pump is the:

direction of rotation

type of oil usef

inlet and outlet vanes

number of inlet and outlet ports

Correct! Wrong!

An open center hydraulic system can best be described as one in which:

pump oil flow is not circulated until a demand is imposed with operator controls

pump oil flow recirculates freely to the reservoir in the neutral position

pump oil flow is not unloaded to the reservoir in the neutral position

the hydraulic storage tank does not have filters inside the tank

Correct! Wrong!

A four connection (four way) spool valve is used in conjunction with a:

double acting cylinder

single acting cylinder

telescoping ram

ram type cylinder

Correct! Wrong!

In the illustration below, what type of hydraulic system is being illustrated?

an open center system

a closed center system

a non-positive displacement system

a fixed displacement system

Correct! Wrong!

A hydraulic system seems to be functioning normally in all other circuits within the system. However, a noticeably decreased free load hydraulic motor speed would most likely be caused by worn pump housing. What other possible cause must be checked?

low supply tank fluid level

low of pump pressure

decreased oil flow

excessive pump pressure

Correct! Wrong!

In a system with a variable displacement pump, the volume of the fluid moved by the pump will:

decrease when the system pressure drops

stay the same when the system pressure drops

decrease when system demand drops

stay the same when system demand increases

Correct! Wrong!

A cylinder tends to creep down when stopped in mid-stroke. the control valve checked out as operational and there is no external leakage. The next thing to check for would be:

high viscosity oil

internal leakage

low vicosity oil

an accumulator problem

Correct! Wrong!

When replacing a hydraulic pump you should:

make certain the new pump has the same rotation, flow and pressure ratings

make sure the threaded holes are compatible or that adaptors are available

pour oil into the pump to pre-charge and ensure initial lubrication

all the above are correct

Correct! Wrong!

The figure below indicates

gas charged accumulator

air charged accumulator

weight loaded accumulator

spring loaded accumulator

Correct! Wrong!

A truck owner complains that his power steering system works fine but is overheating. The oil level is correct, the fluid appears clean and clear and the hydraulic cooling system seems right. What would you do next?

change the pump, and the problem will go away

check the system pressure in the neutral position

check to see if the relief valve set pressure is too high

check all hoses for heat damage

Correct! Wrong!

A double acting cylinder is a device that converts fluid power into:

linear motion in one direction

linear motion in two directions

rotary motion in one direction

rotary motion in two directions

Correct! Wrong!

Hydraulic pumps are rated in terms of:

pressure, speed and gear size

volume at a specified RPM and working pressure

watts of power at a specified RPM

volume measured in litres per hour

Correct! Wrong!

The principle of the operation of a hydraulic motor is:

work is done by fluid flow under pressure

mechanically turned to produce fluid flow

the same as a hydraulic pump

work is done mechanically, and controlled hydraulically

Correct! Wrong!

The figure below indicates

gas charged accumulator

air charged accumulator

weight loaded accumulator

spring loaded accumulator

Correct! Wrong!

The figure below represents a:

weight loaded accumulator

single acting cylinder

spring loaded accumulator

pressure actuated receiver

Correct! Wrong!

The device below represents a

pressure control valve

volume control valve

directional control valve

spring return cylinder

Correct! Wrong!

The device below represents a:

pressure limiting control valve

single acting control valve

open center control valve

closed center control valve

Correct! Wrong!

The device below represents a:

pressure limiting valve

pressure reducing valve

pressure relief valve

flow limiting valve

Correct! Wrong!

On a troubleshooting job, why would it be important to take mechanical drawings for a piece of equipment as well as the hydraulic schematic?

to help identify the piece of equipment

to show others you are well prepared

to help identify the precise location of components

to help verify test results and normal operation

Correct! Wrong!

Causes of lack of hydraulic power to do the work problem might well be the fault of

hydraulic pump, hydraulic motor, directional control valves

engine, hydraulic pump, drive

hydraulic pump, hydraulic motor, hydraulic actuators

hydraulic pump, hydraulic actuators, directional control valve

Correct! Wrong!

When testing a hydraulic system, technicians will monitor and test for:

hydraulic fluid flow and pressure

hydraulic fluid flow and temperature

hydraulic fluid flow, temperature and cycle times

hydraulic fluid flow, pressure, and temperature

Correct! Wrong!

Flow meters have a load valve on them. Before starting the equipment to run tests, the load valve should be

turned to the fully applied position

turned to the fully released position

it depends on what you are testing for

it can be left half way to be safe

Correct! Wrong!

If a loader bucket drops slightly while holding a load, with control valve in neutral position, it might be caused by

control valve not centering properly

oil leaking past cylinder packings or 0-rings

oil leaking past control valve or a relief valve

all of the above

Correct! Wrong!

If a pump is cavitating, it may be an indication of

a clogged inlet screen

an improperly installed canister filter

a damaged filter 0-ring

all of the above

Correct! Wrong!

An indication of an internal hydraulic leak caused by an improperly seated main relief valve may show up as:

lower fluid operating temperature

normal fluid operating temperature

increased system pressure

decreased system pressure

Correct! Wrong!

Restricted flow of hydraulic fluid through a heat exchanger (cooler) may show up as

decreased system pressure

increased system pressure

higher fluid operating temperature

lower fluid operating temperature

Correct! Wrong!

In a confined hydraulic system (floor jack), the force produced will increase as the area of the output piston decreases.

True

False

Correct! Wrong!

Inspite of their speed, smaller diameter pistons are not always more efficient for hydraulic cylinders chiefly because they:

generate less output force than larger pistons

are more liable to let in contamination

create too much friction

operate less smoothly

Correct! Wrong!

With respect to their ability to create flow, hydraulic pumps are classed as

positive or fixed displacement

positive or non-positive displacement

variable or non-positive displacement

fixed or variable displacement

Correct! Wrong!

Hydraulic pumps are rated for:

output force, pressure and flow rate

displacements, output force and pressure

pressure, displacement and flow rate

output force, displacement and flow rate

Correct! Wrong!

To prevent pressure buildup on a pump, the pump circuit would be equipped with a

direction control valve

pressure sequence valve

volume control valve

pressure relief valve

Correct! Wrong!

The device included in many hydraulic systems to help reduce noise, vibrations and shocks to the system is

an oil cooler

a reservoir

an accumulator

a cylinder

Correct! Wrong!

Above ________________ hydraulic oil undergoes chemical changes that lead to rapid oxidation.

82 C (180 F)

95 C (200 F)

110 C (230 F)

121 C (250 F)

Correct! Wrong!

Most oil-to-water hydraulic coolers use the coolant from engine cooling system.

True

False

Correct! Wrong!

In a system with a variable displacement pump, the volume of fluid moved by the pump will

decrease when the system pressure drops

stay the same when the system pressure drops

increase when the system pressure drops

move to zero

Correct! Wrong!

Fixed displacement pumps are usually used in open-centre systems, while variable displacement pumps are used in closed-center systems.

True

False

Correct! Wrong!

The two types of vane pump are the:

axial and in-line

balance and unbalanced

axial and unbalanced

non-positive and balanced

Correct! Wrong!

Piston pumps are more common on low pressure hydraulic systems than on high pressure ones.

True

False

Correct! Wrong!

In an axial piston pump, the distance the pistons can travel back and forth in their bores is controlled by:

the volume of oil pumped

the angle of the swashplate

inlet check valves

manual spring settings

Correct! Wrong!

The three most common types of hydraulic motors are:

fixed, variable, positive

gear, vane, piston

external, internal, radial

positive, non-positive, radial

Correct! Wrong!

The technical name for the rotary output of a hydraulic motor is

force

load

energy

torque

Correct! Wrong!

When you select a hydraulic motor for a specific application, the most useful rating to know is its:

foot-pounds

torque per 100 psi input

torque per 100 psi output

horsepower

Correct! Wrong!

Relief valves are of two basic types

direct-acting and indirect-acting

direct-acting and pilot-operated

pilot-operated and indirect-acting

direct-acting and popper-operated

Correct! Wrong!

What is the internal volume in cubic feet, of the hydraulic tank below: Height = 16 3/4" Length = 24.5" Depth = 15" Wall thickness = 1/4"

471.2 cu.ft.

39.2 cu.ft.

3.9 cu.ft.

3.3 cu.ft.

Correct! Wrong!

What is the internal volume of the hydraulic tank below, in cubic meters: Height = .33 M. Length = .75 M. Depth = 2.0 M. Wall thickness 4 mm

.495 Cu.M.

.476 Cu.M.

.485 Cu.M.

.403 Cu.M.

Correct! Wrong!

What is the volume of the hydraulic tank below? Internal diameter = .75 M. Internal length = 2.0 M.

.883 Cu.M.

3.53 Cu.M.

8.83 Cu.M.

.353 Cu.M.

Correct! Wrong!

What is the volume of the hydraulic tank below? Internal diameter = 24" Internal length = 72"

2712.9 cu.ft.

226 cu.ft.

188.4 cu.ft.

18.84 cu.ft.

Correct! Wrong!

What is the area of the big piston end from a cylinder, if the diameter of the piston is 6 1/4"

19.625 sq.in.

122.6 sq.in.

33.4 sq.in.

30.66 sq.in.

Correct! Wrong!

What is the effective area of the rod end of a hydraulic cylinder piston if the piston diameter is 4 1/2" and the rod diameter is 1.125"

14.9 sq.in.

10.59 sq.in.

8.94 sq.in.

13.18 sq.in.

Correct! Wrong!

To evaluate a hydraulics system, when flow and pressure testing a piece of equipment, the flow rate is best defined as:

a measure of the volume of fluid that passes a given point in a given time

a measure of the speed of fluid that passes a given point in a given time

the average speed of a fluid past a given point

a rating of the viscosity of hydraulic oil while in motion past a given point.

Correct! Wrong!

The difference between an unbalance vane pump and a balanced vane pump is the:

An open center hydraulic system can best be described as one in which:

A four connection (four way) spool valve is used in conjunction with a:

In the illustration below, what type of hydraulic system is being illustrated?

A hydraulic system seems to be functioning normally in all other circuits within the system. However, a noticeably decreased free load hydraulic motor speed would most likely be caused by worn pump housing. What other possible cause must be checked?

In a system with a variable displacement pump, the volume of the fluid moved by the pump will:

A cylinder tends to creep down when stopped in mid-stroke. the control valve checked out as operational and there is no external leakage. The next thing to check for would be:

When replacing a hydraulic pump you should:

The figure below indicates

A truck owner complains that his power steering system works fine but is overheating. The oil level is correct, the fluid appears clean and clear and the hydraulic cooling system seems right. What would you do next?

A double acting cylinder is a device that converts fluid power into:

Hydraulic pumps are rated in terms of:

The principle of the operation of a hydraulic motor is:

The figure below indicates

The figure below represents a:

The device below represents a

The device below represents a:

The device below represents a:

On a troubleshooting job, why would it be important to take mechanical drawings for a piece of equipment as well as the hydraulic schematic?

Causes of lack of hydraulic power to do the work problem might well be the fault of

When testing a hydraulic system, technicians will monitor and test for:

Flow meters have a load valve on them. Before starting the equipment to run tests, the load valve should be

If a loader bucket drops slightly while holding a load, with control valve in neutral position, it might be caused by

If a pump is cavitating, it may be an indication of

An indication of an internal hydraulic leak caused by an improperly seated main relief valve may show up as:

Restricted flow of hydraulic fluid through a heat exchanger (cooler) may show up as

In a confined hydraulic system (floor jack), the force produced will increase as the area of the output piston decreases.

Inspite of their speed, smaller diameter pistons are not always more efficient for hydraulic cylinders chiefly because they:

With respect to their ability to create flow, hydraulic pumps are classed as

Hydraulic pumps are rated for:

To prevent pressure buildup on a pump, the pump circuit would be equipped with a

The device included in many hydraulic systems to help reduce noise, vibrations and shocks to the system is

Above ________________ hydraulic oil undergoes chemical changes that lead to rapid oxidation.

Most oil-to-water hydraulic coolers use the coolant from engine cooling system.

In a system with a variable displacement pump, the volume of fluid moved by the pump will

Fixed displacement pumps are usually used in open-centre systems, while variable displacement pumps are used in closed-center systems.

The two types of vane pump are the:

Piston pumps are more common on low pressure hydraulic systems than on high pressure ones.

In an axial piston pump, the distance the pistons can travel back and forth in their bores is controlled by:

The three most common types of hydraulic motors are:

The technical name for the rotary output of a hydraulic motor is

When you select a hydraulic motor for a specific application, the most useful rating to know is its:

Relief valves are of two basic types

What is the internal volume in cubic feet, of the hydraulic tank below: Height = 16 3/4" Length = 24.5" Depth = 15" Wall thickness = 1/4"

What is the internal volume of the hydraulic tank below, in cubic meters: Height = .33 M. Length = .75 M. Depth = 2.0 M. Wall thickness 4 mm

What is the volume of the hydraulic tank below? Internal diameter = .75 M. Internal length = 2.0 M.

What is the volume of the hydraulic tank below? Internal diameter = 24" Internal length = 72"

What is the area of the big piston end from a cylinder, if the diameter of the piston is 6 1/4"

What is the effective area of the rod end of a hydraulic cylinder piston if the piston diameter is 4 1/2" and the rod diameter is 1.125"

To evaluate a hydraulics system, when flow and pressure testing a piece of equipment, the flow rate is best defined as:

Success!

Heavy-Duty Mechanic - Trucks & Equipment