190303gA : tracked equipment steering part a

Question 1

what causes the turn on a non modularized bulldozer steering?

Answer 1

disconnecting the power flow to one track causes power from the opposite track to push it in the desired direction

Question 2

What would cause a gradual turn on a dozer?

Answer 2

just disconnecting the steering clutch

Question 3

What would cause a sharp turn?

Answer 3

applying the brake and disconnecting the clutch on the same side

Question 4

What is cross steering?

Answer 4

when a dozer is heading downhill and direction is chosen to go in, under normal conditions, right lever would control right steer, in a cross steer condition, it would be opposite to normal steering down a hill

Question 5

What causes cross steering? (in relation to steering)

Answer 5

the weight of the track pushes it in the opposite direction

Question 6

An operator goes to turn right on a non modularized machine, and the machine stops : what component has failed?

Answer 6

the left side steering clutch has failed

Question 7

What keeps the steering linkages in there normal position on a modularized dozer?

Answer 7

springs acting on the linkage

Question 8

what is a deceleration pedal?

Answer 8

decelerates when going in different directions

Question 9

how many positions does each steering lever/handle have and what do they control at each stage?

Answer 9

each lever has 3 positions: 1st position: clutch engaged, brake off. 2nd position: clutch disengaged, brake disengaged. 3rd position: clutch disengaged, brake engaged

Question 10

what disengages the steering clutch? what applies it, and what is its “normal” state? also what is the actual name of the clutch? (for a non modularized dozer)

Answer 10

hydraulic pressure disengages the steering clutch, spring pressure applies it, and its normal state is always engaged: spring applied, hydraulic released clutch

Question 11

What disengages the brake? what engages the brake? on a non modularized dozer? what is it called? what type of brake is it?

Answer 11

springs disengage the brake, hydraulic pressure applies the brake, it is called a hydraulically applied, spring released : also it is a brake band type brake

Question 12

A machine pulls into the shop with a steering complaint You diagnose the problem and you find that : it wont drive straight, pulls to the left, it won’t turn right very well, or sometimes not at all, and when you engage the left brake it won’t stop, when you engage the right brake, it rolls forward a bit going right, what would your pressure gauge indicate? and what component could possibly be the issue?

Answer 12

pressure gauge would indicate that pressure would be supplied to the left hand clutch which would disengage the steering clutch and indicate that the steering control valve has excessive leakage

Question 13

going forward, where is the braking force on the brake band on a non modularized dozer? and which way is it pulled?

Answer 13

the braking force is on the backside of the band, it is pulled counterclockwise

Question 14

going in reverse where is the braking force on the brake band on a non modularized dozer? and which way is it pulled

Answer 14

the braking force is on the frontside of the band, and is pulled clockwise

Question 15

What is the normal condition of the clutch and brake assemblies on a modularized dozer steering system?

Answer 15

the clutch and brakes are both spring applied hydraulically released

Question 16

What benefits does the modularized dozer steering components have over the non modularized?

Answer 16

The brakes are a wet type, the brakes are engaged when machine is shut off, whereas the non modularized you have to have your parking brake on, as it is hydraulically applied spring released

Question 17

operator has a steering complaint about a dozer, what is the first thing to check before assuming it is a clutch issue?

Answer 17

track chain tension, as it can cause issues with tracking first, rule that out before assuming it is a clutch or brake issue

Question 18

What would the complaint be if brakes on a modularized dozer had the left side brakes stuck on (no pressure to brake clutch)

Answer 18

low power going forward, disengaging the left clutch would turn sharp and disengaging the right clutch would not allow it to turn right very well

Question 19

you are able to control steering and braking force with the brake valve True or False

Answer 19

true

Question 20

A high stall speed pertaining to steering clutches in all transmission ranges would indicate what?

Answer 20

slipping steering clutches

Question 21

What is the procedure to correctly perform a stall test?

Answer 21

brakes and parking brake locked up, full throttle and highest gear selected, then check engine RPM and compare to manufacture specifications

Question 22

why is it a good idea to coat parts with oil after disassembly and cleaning?

Answer 22

to prevent rusting of components if they sit out for a long period of time.

Question 23

What is the proper procedure for cleaning bearings and friction discs? and why?

Answer 23

should only be cleaned using mineral spirits, as cleaning with anything else may damage them

Question 24

What is warpage and cone of a friction disc and steel disc measured with?

Answer 24

a level surface and feeler gauges

Question 25

What components are a good idea to replace when you have the steering clutches and transmission out in a dozer?

Answer 25

The bevel gear and shaft

Question 26

If a steering clutch linkage rod adjustment is too short what would be the issue created on a non modularized dozer?

Answer 26

the clutch would be released and cause slippage

Question 27

If a steering clutch linkage rod adjustment is too long what would be the issue created on a non modularized dozer?

Answer 27

The clutch would be released, however it would not fully release

Question 28

If a brake linkage was adjusted too short what would be the issue created on a non modularized dozer?

Answer 28

The brakes would be partially applied

Question 29

If a brake linkage was adjusted too long what would be the issue created on a non modularized dozer?

Answer 29

The brakes would never fully apply

Question 30

how would you do a brake clearance adjustment on a non modularized dozer? what would you do if you run out of adjustment and brakes still won’t work properly?

Answer 30

tighten the adjustment bolts on the band brake, if you run out of adjustment, the band brake should be replaced

Question 31

how is the power delivered through the power train on a dozer? and how come?

Answer 31

through the friction discs on the steering clutch, the springs apply the clutches and hydraulic pressure releases them

Question 32

what dangers will you face in removing clutches on a non modularized dozer?

Answer 32

strong spring force could potentially harm the technician

Question 33

Non-modularized brake systems use what type of brake?

Answer 33

The brake is a wet contracting band type

Question 34

What’s another name for a bevel gear shaft?

Answer 34

The cross shaft

Question 35

True or false. Brake linkage adjustments are made after the clearances adjusted between the brake band and drum

Answer 35

True. Tighten the band all the way, back off one and a half turns. Then make any necessary brake linkage adjustments

Question 36

Pressure gauge reading should be done at what rpm?

Answer 36

low idle and high idle

Question 37

A pressure gauge installed before braking circuit should read on a non-modularized dozer?

Answer 37

0 psi

Question 38

A pressure gauge installed before braking circuit should read what on a modularized dozer?

Answer 38

system pressure as the brakes are disengaged with hydraulic pressure and always engaged with spring tension

Question 39

Cooler bypass valve opens when?

Answer 39

Excessive restriction in cooler is found. If not the lube circuit oil starvation occurs

Question 40

how long should composite friction discs be soaked for?

Answer 40

20 minutes to 24 hours

Question 41

what should piston sealing surfaces be checked for?

Answer 41

wear, nicks, scratches and scoring