Both Octos Leaking Bubbles from Mouthpiece, just serviced

[halocline]

I suspect the elevation was a bit of a red herring. Did you test the regs by diving at sea level after the service but before this trip? When you tested the regs at sea level after the trip, was it with a tank that had the same pressure as when they leaked, or was it the near empty tanks from your trip? Depending on the 1st stage, this could make a pretty big difference.

It might be helpful to know what model 1st and 2nd stages these are.

If you have all sorts of time and curiosity about it, try taking another trip to altitude, this time with an IP gauge. Measure the IP at altitude, and measure it again at sea level, making sure that you are using a completely full tank each time. It should read a bit lower at altitude; that's because the IP gauge is measuring PSIG, not PSI above ambient. Then you could compare atmospheric pressure between sea level and your specific elevation to see if the differences match. They should, but then again the typical IP gauges we divers use are notoriously inaccurate.

As I mentioned, its not uncommon for 2nd stages, especially unbalanced 2nds, to leak a bit after service, if they are set very lightly and sit around a while after servicing. Sometimes a dive or two can sort of break in the seats and stop the leak. It's a bit counterintuitive but I've seen it happen.

 

[BRT]

This is a good reason not to service regs. Right after service is the most common time to have a problem.

 

[Peter69_56]

I admit that my language was probably wrong, I am not a reg technician and am still learning how regs work. I would say that at elevation both octos had a slight hiss the second I hooked them up to the tank by the truck. This hiss continued once at the surface and ceased once ~two feet deep. I'm not saying you are wrong, I'm just saying that empirically, the only variable that changed was the altitude. When hooking up the regs at sea level, the hiss is gone.

Respectfully,
Tim

Only time I have seen this is when the 1st stage has IP creep. It can blurt on and off if the IP creep is so slight, or be constant if the IP creep matches the air loss through the octo. Always seems to be the Octo that free flows and not your normal reg.

Saw one last weekend, just serviced and was blurting off and on. Once under the water it settled down, but needed a re-service.
My wife's Octo did the same when near new, thought it was the Octo but found swarf in the primary reg from manufacture (an Oceanic CDX-5).

I just serviced my wife's regs and I had slight IP creep and this showed a slight air leak on the Octo. Maybe the 1st stage has settled down if it was originally an O ring issue.

 

[ams511]

What is consistent is that higher pressure (being in San Fran or 2 foot deep) stopped the regulators from free flowing. I wonder if the problem is not with the IP but with the second stages themselves.

 

[TinFins]

I spoke with the shop that serviced them, they said the IP was perfect with no creep before and after service. I really would like to know what's going on, I am heading to Bonaire in two weeks and would hate to have my regs fail halfway through the trip.

Should I take the regs back for service?

---------- Post added February 20th, 2015 at 08:25 AM ----------

And to be clear, they were not fully free flowing, just a slight steady stream of small bubbles.

 

[halocline]

I spoke with the shop that serviced them, they said the IP was perfect with no creep before and after service. I really would like to know what's going on, I am heading to Bonaire in two weeks and would hate to have my regs fail halfway through the trip.

Should I take the regs back for service?

---------- Post added February 20th, 2015 at 08:25 AM ----------

And to be clear, they were not fully free flowing, just a slight steady stream of small bubbles.

If you answer the questions I posted, (what kind of regs, did you test before going to altitude, etc) I might be able to help you more. But probably the answer is just that the alternates were tuned a little lightly and needed to break in a bit. I take it you do not have access to a tank at your house? If so, you can probably adjust it yourself at home, thereby making sure it's done correctly. It's not rocket science. Unbalanced downstream 2nd stages often leak a bit just after service as I mentioned before. It's easy to fix this yourself.

 

[Hickdive]

New LP seat has bedded in. Take them back to the shop to have them adjusted.

Alternatively, remove the 2nd stages from their hoses and look inside. There will be a hole with either a hex profile or a couple of slits for a screwdriver. This is the LP orifice.

Using an appropriate sized hex key or screwdriver turn the LP orifice clockwise through five minutes of arc. Depress the purge button whilst turning.

Put the second stage back on the hose and check if the leak is resolved AND the purge button still works.

Repeat if necessary until issue is resolved. If purge stops working repeat whilst turning the LP orifice anticlockwise until purge works and leak is resolved.

If you can't get the leak to stop and still have a working purge then take it back to the shop.

 

[LeadTurn_SD]

...As I mentioned, its not uncommon for 2nd stages, especially unbalanced 2nds, to leak a bit after service, if they are set very lightly and sit around a while after servicing. Sometimes a dive or two can sort of break in the seats and stop the leak. It's a bit counterintuitive but I've seen it happen.

1+. The majority of 2nd stages I use for "octos" are unbalanced, classic downstream 2nd's. It can be quite frustrating, but after changing the soft seat they can be a little "leaky", often randomly, for a few dives; no amount of cycling post-rebuild seems to prevent it... it is like the soft seat just breaks in on its own schedule; then suddenly it is stable and no more leaks. Weird, but yeah, I've seen that too.

TinFins: I still believe the "leaking" was most likely a "tuning" issue with those octos, but if they've stopped leaking and are currently performing normally, I would not be overly concerned. In cases like this, the first thing to test whenever you have a leaky 2nd stage is the 1st stage IP. If the IP is not in the correct range and stable, you'll be chasing your tail trying to tune the 2nd stage. Just because the dive shop tested the IP post-service and it was fine at that time does not necessarily mean that it is still fine. If there is a problem, you need to re-check it to rule out the 1st stage as the source of the problem. Chances are that it is just fine, but you need to check to be sure. Once the 1st stage IP is confirmed as "ok", then you can move on to investigating the 2nd stages themselves as the culprits.

Best wishes.

 

[Peter69_56]

Buy yourself a cheap IP pressure gauge that plugs into your inflator hose. Pressure the system and leave for 20 min and see if the IP has crept up and is leaking, if not then its probably the octo as per other posts.

The cheap IP pressure gauge is something that's good for quick diagnosis on the run. I bought one off ebay which I carry with me. AT home in my workshop I have a quality IP pressure gauge and magnehelic gauge for setting the regulators up properly .

 

[TinFins]

The octos were both tuned too light, I adjusted the LP orifice (thanks HickDive) and everything works perfect now. The purge (at sea level and altitude) was ready to blast with the weight of a fly. Now it is more reasonable.

IP pressure was checked before and after, it was functioning as expected.

Thank you to everyone on this topic, after a 2nd stage lesson from my lds I understand altitude "can't" have an effect on this, but it does ever so slightly. As with most things in life perfect systems are usually not so.