Aqualung Legend MBS leak from Adjuster

[Tigerman67]

So I have a Aqualung Legend MBS that is leaking from the adjuster knob after being serviced by my local dive shop.

I saw a couple of other threads that said discovered that it was either a wrong sized oring or a damaged oring causing this issue. (with a suggestion of changing to an 2-011 duro 90 oring that was more durable)

My problem is, that after discovering the problem in the pool after the service, the LDS serviced it again, and while not as bad this time, and basically just leaking during inhalation now.

The LDS has it again, but I am running out of time before a trip to Palau for them to resolve it. Basically I probably won't have time to schedule another pool session before I have to pack it up to leave.

So trying to understand how they could have gotten it wrong twice in a row.

Trying to find the parts diagram for the MBS, and it seems I can only find the ones for the regular legend, or the Legend Elite or the older model Legends like the Legend LX.
Does the service kit cover a bunch of different regs or variants, and does that cause there to be extra o rings in the kit that could cause them to use the wrong size?

Any know if there are any decent dive repair shops in Palau, if I have to have this looked at again while I am out there?

 

[Tanks A Lot]

Without seeing exactly where the leak is coming from it is a bit hard to pinpoint. If it is truly on the knob itself, there are two O-rings that could be responsible. If it is just the general area, there is one more O-ring in question.

From the attached schematics, it is either O-ring #17, #27 or #29 or their respective sealing surfaces.

Seeing as this happened twice in a row, O-ring damage is unlikely, although not impossible. I guess someone scratched the sealing surface of one of the parts that one of the three above mentioned O-ring sits in. #27 is the "hardest" to remove, so that would be my armchair guess, but any of the others could equally be the culprit.

Damage can occur very quickly with wrong tools or wrong usage of tools, name sharp pointy O-ring picks being used wrongly.

 

[Tigerman67]

After the second time of having a leak, I did remember I actually had my phone case with me (selfy camera is a bit fuzzy though since It shoots through the membrane on the Divevolk case).


Based on some previous threads with people that had similar problems of leak during inhalation, I think they were referring to 29 in this diagram causing the problem. With it either being damaged during assembly or accidently installing the wrong sized oring in that location. The wrong sized oring came up in 2 different posts, so I was curious if there were enough extra oring in this kit that a mistake like that could be made easily, or if there aren't extra orings, does that mean that it was swapped accidently with one of the other orings? (and that I potentially have a wrong sized oring somewhere else too because they were accidently swapped?)

To add to the confusion, it looks like a couple of years ago, aqualung changed the part numbering system to the current system, but in the exploded diagram, it uses the new part number for multipack orings, vs the service kits which has the new part number for individual orings, so can be tough to know the cross reference. Looking at the image of what i think is the service kit for my reg (RA121128?), looks like there are 3 oring sizes that are roughly simliar and could potentially be swapped accidently, I just don't know if they are all normally used as part of service, or it just depends on what reg you are serving what parts you end up using/not using in the kit.

And a few years ago, they also changed the service parts kits to become more specific for some regs.

Basically because of this problem, I have been trying to read everything I can get my hands on to make sure i understand the reg. @Tanks A Lot Do you happen to have an MBS specific service manual as well as the diagram. I found service manuals for the regular Leg3nd, and the Leg3nd Elite. I assume the service would be closest to the Elite. But if there is an MBS specific one, I'd certainly take the time to read that one as well to increase knowledge.

Thanks