Adjusting my Mares Proton Metal (42) - Freeflowing!

[TimorDiver]

Hello Mares,

I have had the proton metal for about 18 months now. For the first year it was a FANTASTIC reg. Like, NEVER have I dived off such a good reg. However, after a year it started freeflowing just a bit at shallow depths. Usually it would stop under pressure. I live in East Timor, so there are no service centres here. Finally one dive it freeflowed madly, I lost 80 bars in 5 mins, lucky it was just as I descended. So I stopped diving off it until I could get it serviced.

Fast forward to now, it has just come back from Australia where it was serviced by a Mares technician. On my second dive, it was still gently freeflowing a bit! Then, when I came out of the water, it was freeflowing constantly until I turned my tank off.

i have been told not to bang the reg so there is little I can do when it starts to freeflow. The service centre in Australia told me that aside from opening up the second stage and cleaning it, there were some other adjustments that could be made under the metal bit on the second stage. This is where he tinkered and changed an o-ring.


So, (finally) my question is: can I make these adjustments myself? If so, can you give me some basic instructions on what I could do to stop the reg freeflowing?

I realise that in a perfect world I would just send it back to the service centre... but I have to wait until someone goes to Australia who could take it over there, easier said than done. We do have a very good dive shop here but no Mares technicians.

Thanks for any advice you can give me.

TimorDiver

 

[Phil Mintz]

Hi,

From the description is seems that it simply needs adjusting, or possibly a full service. I understand your dilema, but we cannot describe how to service your reg on your own via a chat board, sorry.

If it does just need a slight adjustment and while it is not something we reccomend, maybe one of the technicians at your local shop can take a look for you.

regards,

Phil

 

[TimorDiver]

Hi Phil,

Yes, I understand that I shouldn't adjust things myself. (Wishful thinking!)

I am just frustrated because the reg (1st and 2nd stage) has just come back from being fully serviced by a Mares technician in Brisbane, Australia, and it is presenting EXACTLY the same problem.

This seems to be a design fault with this regulator, and it's unfortunate since this reg is a superb breather, advertised as 'top of the line' and expensive - I really expected it to perform well for longer than 18 months.

I suppose I have no choice but to send it back to a service centre - after only 3 dives since a full service. I would appreciate your advice on if there is a Mares service centre in or around Darwin, Northern Territories, Australia.

Thanks.

 

[TN Traveler]

I don't think this is a design flaw with this reg - my wife has been diving hers for over a year and I have been using one for just over 6 months, with no problems. Plus she used a V-32 with Proton Metal 2nds for 2 years with no problems. I think your tech failed to cycle the reg after the rebuild and then perform a final adjustment. The Proton Metal 2nd is super reliable.

 

[redacted]

It is a shame that a minor adjustment that should only take minutes is such a problem. I am not familiar with Mares adjustment procedures but understand they recommend making such adjustments at the demand lever lock nut rather than the poppet seat (orifice). Hopefully, someone with some specific experience with Mares will come along and help. If it were my regulator, I'd remove the front parts of the case and adjust the demand lever lock nut about 1/12th of a turn looser (counter-clockwise). Such an adjustment must be made with the demand lever depressed to avoid damaging the seat. If that did not correct the problem, then resolution may require more than a simple adjustment.

 

[TN Traveler]

Actually, on the Proton 2nds, you do not even have to remove the front cover to adjust the demand lever - there a plug you remove and then adjust with a nut driver. Mares regs also have an adjustment at the poppet seat, that is adjusted with a hex wrench. The key is knowing which adjustment method to use.

 

[redacted]

Actually, on the Proton 2nds, you do not even have to remove the front cover to adjust the demand lever - there a plug you remove and then adjust with a nut driver. Mares regs also have an adjustment at the poppet seat, that is adjusted with a hex wrench. The key is knowing which adjustment method to use.

For most classic downstream designs with an adjustable orifice, such a minor adjustment can be made at either point. But I noticed in Oxyhacker's book that Mares recommended making that adjustment at the demand lever. That book, however, pre-date the Proton model. On my Scubapro regs, I like to make that final adjustment at the orifice whenever possible.

Such an adjustment at the orifice would require removing the LP hose and holding down the purge while turning the orifice 1/12th turn clockwise.

 

[TN Traveler]

For most classic downstream designs with an adjustable orifice, such a minor adjustment can be made at either point. But I noticed in Oxyhacker's book that Mares recommended making that adjustment at the demand lever. That book, however, pre-date the Proton model. On my Scubapro regs, I like to make that final adjustment at the orifice whenever possible.

Such an adjustment at the orifice would require removing the LP hose and holding down the purge while turning the orifice 1/12th turn clockwise.

The Protons are nice in that you usually adjust the lever height so that it barely "rattles" when you shake it and then you can make the final adjustment at the orifice. If you set the orifice exactly to Mares specs, then the lever height adjustment is a great fine tune - but if you want the minimum cracking pressure, then using a combination of both adjustments is required.

 

[Phil Mintz]

Hi Phil,

Yes, I understand that I shouldn't adjust things myself. (Wishful thinking!)

I am just frustrated because the reg (1st and 2nd stage) has just come back from being fully serviced by a Mares technician in Brisbane, Australia, and it is presenting EXACTLY the same problem.

This seems to be a design fault with this regulator, and it's unfortunate since this reg is a superb breather, advertised as 'top of the line' and expensive - I really expected it to perform well for longer than 18 months.

I suppose I have no choice but to send it back to a service centre - after only 3 dives since a full service. I would appreciate your advice on if there is a Mares service centre in or around Darwin, Northern Territories, Australia.

Thanks.

I can understand your frustrations, servicing your reg is not easy and it was not done properly (I assume). From the description it seems as TN has stated, it should just be a simple adjustment. Whether the service tech did not perform the proper work, or something happened to it I can't say. What I can assure you is that there is no design fault with this regulator, it has been on the market for some time.

The dilema is most likely it was not adjusted properly by the first tech, so aside from the distance you may not feel comfortable with them. I am not familiar with your region, so I suggest you check Mares - stand for diving go to any section and then look under sales network (top right) to see if there is a service dealer near you. If not then go to Distributors and contact our distributor in Austraila (CBI) and maybe they can offer assistance.

Let us know how it works out, if you need me to ask CBI on your behalf I can.

Regards,

Phil

 

[Greg Barlow]

I have been servicing Mares regs for a long time, and own several of them myself.

I first adjust the orifice depth to the middle of the recommended adjustment range. That varies depending upon the model/design. Next, I adjust the nyloc nut to remove all but the slightest amount of slack. This assures the maximum hard/soft seat separation through the lever's arc of travel. After this adjustment, I use a magnehelic gauge to test the inhalation effort of the second stage. On Proton second stages, this is set at 1.2", and on the Abyss style versions it is set at 1.3". This is due to the case geometry fault of the reg body.

If you reduce the cracking effort of any non-adjustable downstream second stage to be less than the distance between the center of the diaphragm, and the uppermost lip of the exhaust valve then it can free flow while in a face down position. This is correct for most regs, with the exception of regs utilizing the exhaust valve in the center of the diaphragm. In this case, a cracking effort of around 0.6" is usually alright.

If the cracking effort is higher than what I desire, then I back the orifice out one half turn, and then readjust the locking nut. This is done while the lever is fully depressed. Typically on a Mares reg, this will reduce the cracking effort around 0.1-0.2". If the effort is too light, then the orifice depth is increased. Again, the nyloc nut is readjusted.

TN Traveler is correct in checking for the "rattle". When a Mares reg is properly adjusted for lever height, it will slightly rattle. This is the tip of the lever tapping against the diaphragm's metal plate. The reg should never rattle unless it is pressurized. A quick check is to hold the reg and lightly shake it before it is pressurized. Then pressurize the reg and listen for the sound.

BTW, unless I am using a cold water kit, I adjust the IP of Mares first stages to 138-140psi. This works great in cold water, and provides plenty of gas flow for the second stages.

I am a BIG fan of Mares regs. They are robust, simple to service, and offer outstanding performance. With the new tri-material HP seats they are very dependable and long lasting.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine