O R I G I N A L I N S T R U C T I O N
6.8 SWIVEL AIR INLET (74200-12700)
Using an Allen key* remove screw 40 and washer 39.
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Remove swiveling inlet 38.
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Unscrew double male connector 41 from swiveling inlet 38 and remove nylon washer 33.
Using a spanner*, remove drilled bolt 37.
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Remove two nylon washers 33 and air inlet block 35.
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Remove circlip 97 from double male connector 41 using circlip pliers and withdraw sintered filter 96.
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Assemble in reverse order of dismantling.
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Refers to items included in the 74200 service kit. For complete list see page 13.
Item numbers in bold refer to the General Assembly drawing and parts list (pages 18-19).
6.9 DIFFERENTIAL VALVE
Using special flat spanner* unscrew valve locking plug 27, withdraw and remove spring 104 and 'O' ring 29.
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Remove silencer 34 using a spanner* and remove nylon washer 33.
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Push valve piston 28 out from its housing together with 'O' rings 30, 31&32.
Check spring 104 for distortion and renew if required.
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Assemble in reverse order of dismantling.
6.10 HEAD ASSEMBLY
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Remove nose equipment prior to commencing dismantling.
Using spanners* remove spindle 44 and locknut 45.
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Remove return spring locknut 46 using a spanner*.
Remove return spring 47, washer 99 and locking ring 90.
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Check return spring 47 for distortion and renew if required.
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Assemble in reverse order of dismantling.
6.11 REAR CASING
Using an Allen key* remove screw 40 from stroke set finger 88 and lift off bridge washer 95.
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Disengage stroke set finger 88 by pushing it back against spring 89.
Unscrew rear casing 86.
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Remove rear casing rubber band 87 if necessary.
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Extract circlip 84 using circlip pliers* and remove sintered silencer 85.
Complete assembly in reverse order of dismantling. Locate pawl 102 in head before screwing on rear casing 86.
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6.12 DISTRIBUTOR
Using an Allen key* remove two screws 40.
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Withdraw distributor 83 together with air motor end plug 81 and 'O' rings 82&31 taking care not to drop ball 79 and
push rod 78.
Using an Allen key* remove four countersunk socket head screws 58 and withdraw stroke stop 57.
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Pull out two air supply tubes 59 and four 'O' rings 60.
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Assemble in reverse order of dismantling.
6.13 HYDRAULIC PISTON & AIR MOTOR ASSEMBLY (74200-12610)
Wrap adhesive tape around hydraulic piston 54 thread and move assembly backwards slowly and firmly. Using circlip
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pliers* remove circlip 52 and front seal 51.
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Remove 'O' rings 76 and 77.
Using two spanners* separate the hydraulic piston 54 from air motor casing 75. Shim adjustment ring 55, movement
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pivot 56 and 'O ring 101 will come out with hydraulic piston 54.
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Remove air motor assembly out of air motor casing 75, remove circlip 61 using circlip pliers*, then tap air motor casing
75 on bench to free components.
Parts 62 to 74 can be pulled out as an assembly, taking care not to drop pin 74.
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Refers to items included in the 74200 service kit. For complete list see page 13.
Item numbers in bold refer to the General Assembly drawing and parts list (pages 18-19).
E N G L I S H
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