Mares Abyss Metal (42) cracking pressure adjustment

[Harro10]

I have had a couple of problems with the Abyss 42 second stage free flowing (slight free flow after attachment to tank and turning on air). This actually started after having it serviced. It was corrected between dive days by removing the 2nd stage from the hose and adjusting the cracking pressure. This Abyss does not have an external adjustment. Upon returning home I contacted the dive shop that did the servicing and was told that this was the appropriate fix (since it worked). The same problem occurred last month. The same procedure fixed the problem. I would like to carry the the correct tools with me to do this adjustment myself on trips. I know I need two 17mm wrenches to remove the 2nd stage from the hose. Can anyone here tell me the size hex I will need to do the actual cracking pressure. I want to make sure I have the correct size on hand before I start disassembling the Abyss. Thanks.

 

[ferris213]

I am not a regulator expert by any stretch but I had the same problem with my Abyss 42 regs.

The cracking pressure of the second stage shouldn't really need constant adjustment. It sounds like the IP, controlled by the first stage is creeping and causing the second stage to leak. If you keep winding up the cracking pressure on your second stage, especially without checking it, you may increase the work of breathing rate too far.

I'm my case it was caused by the service tech, who turned out to be the unqualified teenage brother of the actual service tech I paid, scratching the seat while he installed it.

If I were you I would take them back to the shop, ask them to test cracking pressure and IP and find out why the regs keep leaking.

 

[Harro10]

Thanks, ferris213. One problem living in a semi-backwater is that there is no local shop that can service my reg. I have to ship it for servicing which has its own pitfalls. I have a dive trip scheduled and I am going to bring the correct tools for an adjustment with me but hopefully do not need them. If I do have to do any kind of tweek I will sent it in back for another servicing and will ask about the IP/seat possibility.
Safe diving.

 

[Fishpie]

The Mares LP seat is very soft and easily takes a set and can need between service adjustments to cure a slight free flow.

Adjustment is a balance between lever height.......adjusted by the locknut in front of the lever, and, orifice position......adjusted with a allen key in the tube exposed when hose is removed.

If (and thats a big if) the original service got these 2 adjustments correct then I would just make the minor adjustment that is necessary by screwing in the orifice.

 

[Harro10]

That is what I am going to be prepared for but hope not to have to do. I am not crazy about the idea of detaching the second stage and adjusting it while on a small moving panga but I will be prepared to do so if needed.

 

[Fishpie]

It's the locknut adjustment that is the tricky one..........removing the hose and simply turning an allen screw 1/10th of a turn is easy.

Get a cheap $15 IP gauge as well. Every diver should have one.

5mm

 

[Harro10]

Thumbs up.