First stage leaking. Cause?

[herman]

Soapy water is the standard way of looking of leaks. Barely crack the valve open and spray the reg with a solution of soapy water (dish detergent). Bubbles with form where the leak is.

 

[АлександрД]

It can be removed, I'm not sure how, but I'll give it a shot (anybody who does know feel free to chime in!).

There is a VERY simple way, how to repair o-ring between DIN connector and regulator body.
It is not good way, when you have instruments or access to regulator service, but "in the field", when you have not another way, and do need to repair - it could be used.
You have to stay regulator without hoses (you can stay it attached, but it could be more difficult to do).

Connect regulator to the tank.
And tighten the DIN nut TIGHTLY! very tightly.
Start to turning regulator body, as you sty to detach it. And keep DIN nut without movement.
It can allow you to disconnect DIN connector from regulator. (and it is the warning, why is forbidden to try regulator turning, when DIN nut tightened up)
Later change o-ring, and attach DIN connector back to the body (more detailed - connect body on the DIN connector)
Then try to thight it, as much, as you can.
Next turning out DIN nut, and do not turning regulator! Even do not touch regulator body, when you turning out DIN nut.
Connect it back to the tank, with light tight (as normal) to the tank. Open valve to check the leakage (absence of leakage).
Getting pleasure.

 

[Perryed]

I remember the first time I overhauled a MK10 and hooked it to to a tank. When I turned the air on these was a big leak. Wondered how I had screwed up so badly. I just had not fully tightened one of the HP ports. When I saw the video here my first thought was a hose o-ring.