S 866-087

 (4)  
Put the control wheel in the neutral position and do not operate the other flight controls.

 (5)  
Measure the system gross leakage and write the value here:

 S 976-088
 Center _______________ GPM (Value No. 1)
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757
MAINTENANCE MANUAL

 S 866-089
 (6)  Put the C FLT CONTROL SHUTOFF switch on the P61 panel to OFF.
 NOTE: This removes center system pressure from the empennage flight
____
 controls.

 S 976-090
 (7)  Measure the system gross leakage for the lateral flight controls and write the value here:
 Center ______________ GPM (Value No. 2)
 S 866-091
 (8)  
Put the speedbrake lever at approximately the middle position between the ARMED and the UP detents.

 S 976-092

 (9)  
Measure the leakage and write the value here:

 Center _______________ GPM (Value No. 3)
 S 976-093
 (10) Subtract Value No. 2 from Value No. 3 and write the value here:
 Center Value No. 3
 minus Value No. 2 = _______ GPM (Value No. 4)

 S 976-094
 (11)
 If Value No. 4 is less than -0.75 GPM, usually you must replace a spoiler PCA because of high seal leakage.

 S 976-095

 (12)
 If Value No. 4 is more than 0.75 GPM, usually you must replace a spoiler PCA because of high null leakage.

 S 976-096

 (13)
 If Value No. 4 is between the above PCA limits, you can not make a decision about PCA replacement until you do the Full Hydraulic System Internal Leakage Check and Isolation of Components with High Leakage procedure.

 (14)
 Put the speedbrake lever to the down-and-locked position.

 S 866-097
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