C. Procedure
 S 868-324
 CAUTION: DO NOT TIGHTEN THE COUPLING ASSEMBLY BY HAND AFTER YOU REMOVE
_______ IT FROM THE SHIPPING CONTAINER OR BEFORE YOU INSTALL IT ON THE TUBE. THE COUPLING ASSEMBLY HAS NO MORE THAN ONE THREAD ENGAGED. YOU CAN COMPRESS THE UNION AND MAKE THE COUPLING ASSEMBLY DIFFICULT TO PUT IN POSITION.
 (1)  Remove pressure from the systems where you will do repairs.
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747-400 MAINTENANCE MANUAL
 S 118-325
 WARNING: DO NOT GET SOLVENTS IN YOUR MOUTH OR YOUR EYES, OR ON YOUR
_______ SKIN. DO NOT BREATHE THE FUMES FROM SOLVENTS. SOLVENTS ARE HAZARDOUS MATERIALS. SOLVENTS MAY BE FLAMMABLE OR HARMFUL TO THE ENVIRONMENT. REFER TO PRODUCT MATERIAL SAFETY HANDLING DATA SHEETS (MSDS) AND LOCAL REQUIREMENTS FORPROPER HANDLING PROCEDURES.
 (2)
Use solvent, Series 80 (AMM 20-30-80/201) to clean the tube in the

 (5)  
Install tape on the nut side of the clearance with a minimum of 0.56 inch from the tube end and a maximum of 0.675 inch from the center of the clearance (Fig. 822).

 S 948-329

 (6)  
Use the same measurements to make a mark (index line) on the coupling side of the tube.

 S 948-330

 (7)  
Find and make a mark (marking dots) on the nut and coupling side of the tube (Fig. 822).

 area where you will install the H-coupling.
 (3)  S 358-326Cut the tube.
 (4)  S 118-327Chamfer and remove burrs from the ID and OD edges. with solvent, Series 80 (AMM 20-30-80/201). Clean the edges
 S 948-328

 NOTE: These marks will be used for the last inspection check
____ (dimension "C").
 S 428-331
 (8)  
Install the coupling assembly over the coupling side of the tube.

 S 218-332

 (9)  
Make sure the large radius and the large diameter end of the sleeve are toward the center of the union.

 S 438-333

 (10)
 Install the nut and sleeve over the tape on the nut side of the tube.

 S 218-334

 (11)
 Make sure the sleeve large bore is toward the clearence.

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MAINTENANCE MANUAL

 S 828-335
 (12)
 Align the tubes and move the union until it touches the tape on the nut side on the tube.

 S 218-336

 (13)
 Make sure the union meets or covers the index line on the coupling side of the tube.

 S 948-337

 (14)
 Install tape on the coupling side of the tube, with the tape edge even with the end of the union.

 S 438-338

 (15)
 Push the sleeve and coupling body on the ends of the union.

 NOTE: Make sure the tape does not move and the coupling body
____
 does not turn.

 S 838-339
 (16)
 Engage the threads of the nut with the coupling body and tighten the nut handtight.

 S 438-340

 (17)
 Hold the coupling body with a wrench and tighten the coupling assembly nut to the stop.

 S 218-341

 (18)
 Examine the completed repair to make sure you can see the two marking dots (Fig. 822). If you cannot see the two dots, this shows that the sleeve and coupling are not fully seated against the center land of the union.

 S 218-342

 (19)
 Make sure dimension "C" did not increase.

 S 208-343

 (20)
 Do an inspection as follows:

 (a)  
Remove the nut.

 (b)  
Make sure the slide and coupling are no more than 0.015 inch from the union shoulder.

 (c)  
Make sure the union touches the tape.

 (d)  
If the clearance between the slide or coupling and the union is more than 0.015 inch, install the nut and tighten it until you get the necessary clearance (Fig. 822).
　
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