Odd little issue with my Mares Proton

[charlesml3]

Hey gang,

I have a little issue with my Proton and I was wondering if anyone else might know what's going on. It's an older model. I think I've had it 8 years or so and it's been serviced regularly since new.

Anyway, when the tank gets down to around 1100 PSI I get a very gentle freeflow out of my 2nd stage. I can barely feel it but if I stop breathing it'll do a slow "glug.....glug..." out of the exhaust ports. Funny thing is, it stops doing this at around 850 PSI.

Seems like right after it's back from service it's fine but starts doing this again within 30 dives or so.

Like I said before, it's not really a big deal. Anyone know what might be causing this?

Thanks in advance...

-Charles

 

[LeadTurn_SD]

Which Mares 1st stage: MR-12? As much additional info as you can provide will help....

My initial advice is that you need to check the intermediate pressure (IP) of the first stage before proceding to any definitive diagnosis.... the IP on most Mares 1st stages is in the 142-148 psi range.

If the IP is stable after "lock-up" (you purge or breath the reg several times, watching the IP dip slightly then quickly return to 142-148 psi, and the IP STAYS there; and does not creep any higher), then procede to checking the 2nd stage for correct adjustment.

The Proton 2nd stage is a "classic downstream" (I own three of them). If the IP creeps up too high it will behave as you describe, but I'd expect it to do it throughout the dive.... but a SLOWLY creeping IP that is just high enough to cause a slight leak may not be noticeable during a dive because each breath drops the IP, then it slowly creeps up, but the next breath drops it again, etc.... but a long pause between breaths might be long enough to get a "burp" out of the 2nd stage is the IP creaps up enough to just overcome the spring pressure in the 2nd stage.... so you need to check the 1st stage IP (did I say that already?? ).

Anyway, let us know what first stage you have. The other thing is that if it is "ok" after service, but begins to leak a little after 30 dives, it could just be the soft seat in the 2nd stage "taking a set" (developing a groove), and it may just need a touchup tuning....

Best wishes.

 

[keyshunter]

Charles,
Is your tech using the newer (tri-material) or the older high pressure seats? Until Mares brought out the new seat a few years ago, their hp seats were a joke. During the few years I dived a pair of Mares regs I almost never had more than 60 dives on a hp seat before the reg started acting as you describe. Although I gave up on Mares some years ago, I have been told that the new tri-material seats are much better.

 

[Greg Barlow]

Charles,
Is your tech using the newer (tri-material) or the older high pressure seats? Until Mares brought out the new seat a few years ago, their hp seats were a joke. During the few years I dived a pair of Mares regs I almost never had more than 60 dives on a hp seat before the reg started acting as you describe. Although I gave up on Mares some years ago, I have been told that the new tri-material seats are much better.

Many of the regs that I have serviced with tri-material HP poppets now have in excess of 100 dives on them. The only ones that I have seen fail with less dives are those which had defective hard seats (volcano orifice). Mares did experience some ongoing issues with the previous HP seat materials. Of course, many other manufacturers have experienced similar issues. I've been working in the industry long enough to have seen companies such as Scubapro make several engineering changes in an attempt to find a soft/hard seat combination that is both long lasting, and provides consistent sealing.

Greg Barlow

 

[Greg Barlow]

Hey gang,

I have a little issue with my Proton and I was wondering if anyone else might know what's going on. It's an older model. I think I've had it 8 years or so and it's been serviced regularly since new.

Anyway, when the tank gets down to around 1100 PSI I get a very gentle freeflow out of my 2nd stage. I can barely feel it but if I stop breathing it'll do a slow "glug.....glug..." out of the exhaust ports. Funny thing is, it stops doing this at around 850 PSI.

Seems like right after it's back from service it's fine but starts doing this again within 30 dives or so.

Like I said before, it's not really a big deal. Anyone know what might be causing this?

Thanks in advance...

-Charles

Without pressurizing the reg, gently shake the second stage. You should not hear a gentle clicking sound. Now, pressurize the first stage and repeat. If the Proton is adjusted properly, there will be a barely audible clicking sound. If no sound is present, the second stage needs to be lightly adjusted.

It is probably not an IP issue, as only occurs at certain cylinder pressures. The first stage is a balanced version, and the IP will remain constant. Have the IP checked, though. An experienced tech can diagnose the problem within 5 minutes.

Greg Barlow

 

[keyshunter]

Without pressurizing the reg, gently shake the second stage. You should not hear a gentle clicking sound. Now, pressurize the first stage and repeat. If the Proton is adjusted properly, there will be a barely audible clicking sound. If no sound is present, the second stage needs to be lightly adjusted.

It is probably not an IP issue, as only occurs at certain cylinder pressures. The first stage is a balanced version, and the IP will remain constant. Have the IP checked, though. An experienced tech can diagnose the problem within 5 minutes.

Greg Barlow

Greg,
When my Mares hp seats went bad, they began to freeflow at all tank pressures.

Please note that I had no issue with the breathing of my Mares regs. They breathed just as well as the AL Sea and Titan first stages I replaced them with. I just became so frustrated at the short hp seat life, as well as the difficulty in obtaining replacements.

 

[charlesml3]

Hey gang,

I've looked all over this 1st stage and I can't find a model number. It's due for a service at AirTech in a few months so I'll tell them what's going on when I take it in.

Thanks!

-Charles

 

[Greg Barlow]

Greg,
When my Mares hp seats went bad, they began to freeflow at all tank pressures.

Please note that I had no issue with the breathing of my Mares regs. They breathed just as well as the AL Sea and Titan first stages I replaced them with. I just became so frustrated at the short hp seat life, as well as the difficulty in obtaining replacements.

Yes, when the seat begins to leak the IP will increase to the point where the second stage with the lowest cracking effort will begin to vent the excessive pressure. This generally occurs whether the cylinder pressure is 300psi or 3,000. The older type seats were very inconsistent in life expectancy. I had some go for more than 100 dives, while some others barely achieved 30. The tri-material valves are very durable, and they offer excellent lock-up with little to no perceptible drift.

The AL Titan is an excellent first stage as well. That, and the Mares MR12, are almost identical internally.

Greg