9-43. 9-44. You are replenishing the hydraulic system with oil, what should you use to strain the oil? 1. A  cheese  cloth 2. An  aluminum  filter 3. A  200-mesh  wire  screen 4. A  400-mesh  wire  screen If  you  are  filling  a  hydraulic  system  and notice water in the oil, what should you do? 1. Centrifuge the oil or reject it 2. Run  the  oil  through  a  200-mesh strainer 3. Heat  the  oil  to  permit  the  water  to evaporate 4. Allow  the  oil  to  stand  until  the water sinks to the bottom Question 9-45 is to be judged True or False. 9-45. Opening  the  air  valves  to  a  hydraulic system will allow any air pockets formed in the unit to vent into the oil expan- sion  box. 9-46. What type of material is used to form the shaft  seal  of  most  modern  hydraulic pumps? 1. Rubber 2. Neoprene 3. Asbestos 4. Flax 9-47. What condition can cause the packing of a shaft  stuffing  box  to  wear  out  quickly? 1. Hard  packing 2. Rough  shaft 3. Shaft  deflection 4. Excessive   packing 9-48. What is the main purpose of packing a shaft  packing  gland  uniformly  and lightly? 1. To allow for cooling and lubrication 2. To  prevent  scoring  of  the  shaft 3. Roth 1 and 2 above 4. To  prevent  binding  of  the  shaft 9-49. Assume that a routine inspection reveals a leak in the line of a hydraulic system at a flanged joint. If the leak persists after the bolts have been tightened evenly, what will be the proper correc- tive  procedure  to  follow  next? 1. Replace  the  flanges 2. Install  new  packing 3. Inspect  the  fluid  for  contaminants 4. Install   square-braided   asbestos packing 9-50. How  should  you  cut  out  an  auxiliary  line of  a  hydraulic  system  if  you  want  the rest  of  the  system  to  continue  to operate? 1. Close  the  valves  of  the  ram  cylinder 2. Cut in a new pump 3. Cut  out  the  three-way  valve 4. Valve  off  the  line  from  the connection  to  the  main  line Questions 9-51 and 9-52 are to be judged True or False. 9-51. The  three-way  valve  in  a  hydraulic  gear installation  may  be  used  to  shift  from the  operating  pump  to  a  standby  pump. 9-52. Replenishing  lines  installed  to  hydraulic systems  of  older  ships  are  a  source  of leakage  troubles  because  pressures  are  in excess of 300 psi. 9-53. The relief valves in a hydraulic system leak. What should you do to the valve seats? 1. Reface  them 2. Replace  them 3. Regrind  them 4. Fit  them  with  seat  inserts 9-54. Which of the following steps should you take  to  correct  an  inoperative  shuttle valve? 1. Replenish  the  oil  supply 2. Secure  the  expansion  tank 3. Adjust  the  valve  to  allow  more  liquid to  flow  through 4. Close  the  stop  valves  and  remove  the valve  for  repairs 59