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D420 Service Manual

 

Use this manual at your own risk.  It is not approved by Scubapro.

 

DIY service of scuba life support equipment may kill you.

 

This manual has been adapted from a copy of Version 1.0, March 2020

 

 D420 SERVICE PROCEDURE, D420 SECOND STAGE GUIDELINES, 

 

DISASSEMBLY, ASSEMBLY, ADJUSTING AND FINAL TEST, 

 

published by Johnson Outdoors.  As no copyright notice was observed on the 

document, any use of copyrighted material is unintended and inadvertent.  

 

The document had apparently been translated from the Italian, and text has 

been modified for clarity where translated phrases were unclear.

 

The author has made additions and modifications based upon his experience, 

which have not been approved by Scubapro. 

 

Use this document at your own risk.

Summary of Contents for D420

Page 1: ...BLY ASSEMBLY ADJUSTING AND FINAL TEST published by Johnson Outdoors As no copyright notice was observed on the document any use of copyrighted material is unintended and inadvertent The document had apparently been translated from the Italian and text has been modified for clarity where translated phrases were unclear The author has made additions and modifications based upon his experience which ...

Page 2: ...be lubricated along with any adjacent moving parts The approved lubricant is Christolube MCG 111 Previous Technician Seminars have indicated that Tribolube 71 is also acceptable though this is not found in official Scubapro publications Note The lubricant container as well as tools and brushes used for service must be perfectly clean free from dust hydrocarbons or other particulate matter Plastic ...

Page 3: ...small pin face spanner Scubapro Multitool PN 43 040 000 or small pin face spanner 3 32 Allen key PN 43 002 101 2mm 5mm and 6mm hex keys O ring pick PN 43 300 107 3 16 wooden dowel or blunt brass pick Small needle nose pliers forceps or tweezers Front Ring Retaining Tool PN 43 404 003 or rubberized jar lid remover Torque wrench PN 43 300 998 6mm Hex drive extension PN 43 040 009 ...

Page 4: ... rubberized pad 6 Carefully lift out the diaphragm thrust washer 41 and the diaphragm 40 7 By using the multi tool function 9 or a face spanner with a counterclockwise motion unscrew the flow vane plug 35 from the case 8 The dive switch 33 and the flow vane washer 32 can then be lifted out O ring 34 may fall out at this time 9 Use a 3 32 Allen key to fully unscrew the small lever hex screw 16 from...

Page 5: ...now be loose Remove it 15 Pushing in an upward direction against the square deflector at the rear of the housing 18 push the housing up and out of the case If it did not fall out in step 13 above the poppet stem assy 49 is accessible and can be carefully removed with a thumb and index finger or small forceps 16 Push the housing support 8 in the direction of the LP hose inlet i e from the opposite ...

Page 6: ...ically follows the format 01 050 xxx In this manual o rings will hereinafter be described only with the last three digits following a decimal point e g 160 as well as with the diagram number in parentheses The full part number will be listed where it does not follow the 01 050 format 3 Lightly lubricate two 160 o rings 7 and carefully fit them into the grooves of the housing support 8 Assure that ...

Page 7: ...e case plug finger tight 9 Place the case flat on the bench in front of you mouthpiece tube facing down Insert the lever 37 from the left side into the oval hole in the housing such that the narrowed flat in the lever is centered Gently allow the lever to drop against the square flap of the housing 10 Insert the hex screw 16 unthreaded end first and using a 3 32 Allen key screw the hex in until it...

Page 8: ...ioned in a 12 o clock 6 o clock orientation Rotate the inner flow vane until its biggest tooth rests at the 12 o clock position with the mouthpiece up 18 Insert the flow vane washer 32 ensuring that when the tab is in the slot of the case the grooves meet the teeth of the flow vane ring 31 Rotate the flow vane ring slightly as needed to allow the washer to fall into place Insert the dive switch 33...

Page 9: ...into the case ensuring that the restraining hook at the bottom of the purge button is inside the cutout in the faceplate Using pressure against the spring to align the holes in the top of the purge button with the holes in the case secure the purge button with the pin 45 Confirm that the pin enters with some friction and that it is symmetric on both ends Operate the purge button and confirm that i...

Page 10: ...47 to the case with the clip 46 or zip tie 8 Place the dive switch in the Pre Dive position forward and confirm that freeflow cannot be initiated with a brisk tap on the purge valve If freeflow occurs in the Pre Dive position confirm that a the mouthpiece is in place b the supplied Intermediate Pressure is 125 145 psi c that cracking effort is at least 1 2 WC and d that the flow vane subassembly h...

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