Mares MR12 DIY

[gulfcoaster]

Just acquired an extremely crud crusted MR12 - opened it up and to my delight it was pristine on the inside, not a scratch or any tarnishing at all. And all the external crud disappeared with the help of my Harbor Freight ultrasonic.

Disassembly and assembly seem fairly straightforward, if not down right easy. But I have a few questions:

Where are the critical lubrication points, besides the 006 o-ring in the hp chamber?

Is the Trident seat A244 a valid substitute? It seams a lot softer than the Mares seat...

This is my first dive into a diaphragm reg and looking for some hints, guidance.

Thanks all !

 

[rob.mwpropane]

Just acquired an extremely crud crusted MR12 - opened it up and to my delight it was pristine on the inside, not a scratch or any tarnishing at all. And all the external crud disappeared with the help of my Harbor Freight ultrasonic.

Disassembly and assembly seem fairly straightforward, if not down right easy. But I have a few questions:

Where are the critical lubrication points, besides the 006 o-ring in the hp chamber?

Is the Trident seat A244 a valid substitute? It seams a lot softer than the Mares seat...

This is my first dive into a diaphragm reg and looking for some hints, guidance.

Thanks all !

Any pictures? I think I have one of these but I haven't opened it up yet

 

[gulfcoaster]

I'll dig up a couple of before and after pics later on....

 

[Jcp2]

Conceptually the same as a Conshelf/Titan, some internal parts even interchangeable.

 

[Zef]

Just acquired an extremely crud crusted MR12 - opened it up and to my delight it was pristine on the inside, not a scratch or any tarnishing at all. And all the external crud disappeared with the help of my Harbor Freight ultrasonic.

Disassembly and assembly seem fairly straightforward, if not down right easy. But I have a few questions:

Where are the critical lubrication points, besides the 006 o-ring in the hp chamber?

Is the Trident seat A244 a valid substitute? It seams a lot softer than the Mares seat...

This is my first dive into a diaphragm reg and looking for some hints, guidance.

Thanks all !

You will find service manual, parts list, and exploded diagrams of your MR12 on among the links at this website

According to the information presented in the dicussions at this link, the Trident A244 is a valid substitute. Note that Mares has made changes to their HP seat/poppet since that discussion thread, one of the change may have been to a firmer seat material, as Mares has tried to make that part more durable.

Bottom line is hte A244 will fit but you may need to replace it more often than the current Mares OEM part. Assuming since you are asking about this part that you have an IP guage and use it periodically to check the health of your first stage, then you shouldn't find yourself dealing with a catastrophic failure down the road.

-Z

 

[gulfcoaster]

You will find service manual, parts list, and exploded diagrams of your MR12 on among the links at this website

According to the information presented in the dicussions at this link, the Trident A244 is a valid substitute. Note that Mares has made changes to their HP seat/poppet since that discussion thread, one of the change may have been to a firmer seat material, as Mares has tried to make that part more durable.

Bottom line is hte A244 will fit but you may need to replace it more often than the current Mares OEM part. Assuming since you are asking about this part that you have an IP guage and use it periodically to check the health of your first stage, then you shouldn't find yourself dealing with a catastrophic failure down the road.

-Z

BOOM! Great links, thank you. Giving this IP gauge a try.... so far so good.

 

[gulfcoaster]

Before:

After:

Anyone know which year model this might be?

 

[axxel57]

Your MR12 1st model should be from around '95, I couldn't tell exact.
For me it's technically a bullet prove Conshelf Clone, very reliable with a very good balancing, technically one of my 'wet' diaphragm favorites.
Me personally, I did not have good experiences with the Trident seats.
They got bridle pretty fast in tropical storage conditions and I had to throw away quite a couple of them, so I used for many years the Aqualung HP Seat 105940 and still use them (I was no Mares Dealer), which was even from Mares for a short time recommended in the early 2000', when Mares had problems with their seats......

 

[rsingler]

For those without access to Aqualung OEM HP seats, the Scubagaskets HP seat SG124624 5510  appears to be similar.

 

[gulfcoaster]

Found this Mares HP seat on eBay - hope it's legit... seller confirmed it's a genuine tri material seat