Removing Orifice/Crown Aqualung Legend

[supergaijin]

Hi all- I have been servicing my Legend LX myself for the last couple of years but always have trouble removing the crown/orifice from the first stage.

As per the instructions given in the service manual:

Insert the pin-end of seat extractor tool (pn 109436) into the center hole on the low pressure side (diaphragm side) of the first stage body. While keeping the pin slightly tilted, press inward to remove the crown (9). Remove the o-ring (8) from the crown.

I don't have this specific tool, but have removed it in the past with a ball-tipped brass pick remover.

IME this removal has always been tough, requiring an alarming amount of force. My question is whether it is possible to use a blast of air from a gun to remove the crown. Would heat in the form of a bath help to loosen the crown?

Regards

 

[axxel57]

Air probably will not help, because there is hardly any area where it could help to push.
I use normally in this cases some liquid silicone which I put on the orifice crown seat. Then I use a plastic pen type tool and gently push this a couple of times against the crown, allowing the silicone to slip between the o-ring and the first stage body. After this treatment usually the crown comes off even without the special tool using carefully whatever you have to lift the crown.
Same should work with soapy warm water. Later I lubricate the crown o-ring with quite some Christolube.
Good luck!

 

[supergaijin]

After re-reading a section in Vance Harlow's book, it seems he uses a similar technique of inserting a dowel rod into the center-hole and blocking the air from flowing through the crown. I will try to fabricate a similar soft-tipped pencil or something like that- should do the trick.

Thanks

 

[cbmech2]

You may also want to put the body on a piece of old neoprene just to protect the crown when it comes out. It only takes one little nick for the crown to be toast.