ScubaPro MK10 leaking air

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

HKGuns

Contributor
Messages
665
Reaction score
621
Location
Merica
# of dives
25 - 49
I use a MK10 on my pony bottle. I picked it up used and had it serviced, before using, at my LDS.

Last night I turned the valve on and the 1st stage is slowly leaking from the top. I know the answer is to get it serviced, but wondering if this should be a clue for me to consider another 1st stage for my pony?

Any idea what would cause this to leak after literally no use and after a winter of just sitting?

The picture below is of the actual regulator and the arrow indicates where the air is leaking from. I don't recall that hole in the middle, but I know literally nothing about these.

Opinions on what may have happened or is going on?

p2397063812-5.jpg
 
From there normally it can only leak if there is a problem with the HP seat or it's position.
Or maybe the seal below the HP seat is damaged.
Anyway no reason to look for another first, your one looks good and it should be quite easy to solve that problem, if you have someone who can open the cap and have a look.......
 
How many times did you use it without the leak between the service at the LDS and the current leak?
 
If it's leaking air from the first, and is not a Sherwood, it's time for service, and it doesn't look like a Sherwood. :wink:
 
How many times did you use it without the leak between the service at the LDS and the current leak?

I probably dove 10 times in fresh water with it on my slung pony. (Its been roughly a year since the service.)

Never breathed from it and usually dove with the valve closed and briefed my buddy on its status prior to entering the water. I rinsed it out very well after each dive as well.
 
Pretty sure diving it with the valve closed could result in water intrusion into the 1st stage. If that is the case it should be rebuilt as it could have debris, damage etc. I'm not 100% on that but I do remember reading that somewhere.
 
I use a MK10 on my pony bottle. I picked it up used and had it serviced, before using, at my LDS.

Last night I turned the valve on and the 1st stage is slowly leaking from the top. I know the answer is to get it serviced, but wondering if this should be a clue for me to consider another 1st stage for my pony?

Any idea what would cause this to leak after literally no use and after a winter of just sitting?

The picture below is of the actual regulator and the arrow indicates where the air is leaking from. I don't recall that hole in the middle, but I know literally nothing about these.

Opinions on what may have happened or is going on?

View attachment 656093
Usually this means the o-ring (or crush seal ring) that seals the lower part of the high-pressure seat retainer and seat in the regulator body is worn out or not seated properly. The hole it’s leaking from is used to extract the high-pressure seat when installing a new one (either with a pin or a burst of pressurized air). Uncommon for this to happen with so little use and this little time post servicing. Odds are the ring wasn’t installed well enough (that one needs to be pressed into place carefully) or wasn’t actually replaced. If you were to unscrew that flat cap with a pin spanner the ring would be in the “hole” of the reg body (purple o-ring or a red crush seal but could also have an aftermarket o-ring that’s black or brown). A reg servicing should fix it (maybe take it to a different shop). It’s a 1 minute job to switch out that o-ring (and high-pressure seat) but you might as well get everything else done too. Great reg btw, do not get rid of it. If it worked fine right after servicing last time it will work fine again. If serviced properly, and well taken care of, they can go many years (5 or more) before needing another service.
 
Usually this means the o-ring (or crush seal ring) that seals the lower part of the high-pressure seat retainer and seat in the regulator body is worn out or not seated properly. The hole it’s leaking from is used to extract the high-pressure seat when installing a new one (either with a pin or a burst of pressurized air). Uncommon for this to happen with so little use and this little time post servicing. Odds are the ring wasn’t installed well enough (that one needs to be pressed into place carefully) or wasn’t actually replaced. If you were to unscrew that flat cap with a pin spanner the ring would be in the “hole” of the reg body (purple o-ring or a red crush seal but could also have an aftermarket o-ring that’s black or brown). A reg servicing should fix it (maybe take it to a different shop). It’s a 1 minute job to switch out that o-ring (and high-pressure seat) but you might as well get everything else done too. Great reg btw, do not get rid of it. If it worked fine right after servicing last time it will work fine again. If serviced properly, and well taken care of, they can go many years (5 or more) before needing another service.

Thank-you for the very detailed description. I may take it apart myself to inspect before taking it to the LDS for service.
 
Mk 10 is very reliable.
My buddy seldom has it serviced over several yrs of use.
BTW, should always pressurize the reg before dropping into water and periodically check the pressure if there is a spg otherwise repressurize it after 10 mins or so.
Luckily your were diving in fresh water.
 
There is the possibility the HP seat is cracked. Sometime ago SP put out a bulletin stating the pistons needed to be changed out to avoid possibly cracking the seat. The old piston had a straight shaft, the replacement has a shoulder.

As stated above, the hole is where a blast of air or a tiny pin pushed through to remove the seat, the former being the usual method.

If it was serviced a year ago take it back to the LDS that worked on it and show (not tell) the problem. They should be able to evaluate it and hopefully fix the problem. There may have been a mistake when it was serviced and now they have the chance to correct the mistake, assuming there was one made.
 

Back
Top Bottom