View Full Version : DIN conversion for Mares MR12

02-23-2009, 14:24
I've ordered a DIN conversion for my MR12 first stage from ST and will pick it up when I visit the states this week. The yoke clamp is held on with a single large nut on the inside of the clamp. I have a few questions about removing this nut:

1. Is it a 1" SAE nut or is it metric equivalent (25mm)?
2. How tight should I expect this nut to be on a relatively new reg? E.g. how difficult will it be to loosen.
3. Will an open-end wrench slipped around one side of the yoke be able to break the nut loose without damaging the nut?

I'm asking for 2 reasons; I plan to do the conversion myself with my own tools (not a problem, I have an engineering and mechanics background) and I don't want to damage the nut as I plan to swap between yoke and DIN as needed. It looks like an open-end wrench may work, as long as the nut is not so tight that rounding off the corners of the nut becomes a problem. Alternatively, a thin-walled box-end wrench would be even better, but it may be harder to find one that is thin enough to fully engage the nut. I don't have the necessary tool so I need to know what would work best.

I live in Finland where almost everything is DIN, but I travel for most of my diving which means yoke, and I don't like using a DIN adapter.

Anyone done this before and have some tips?

03-01-2009, 13:02
One the MR12, I used a crescent wrench because it had deeper jaws. The yoke swivels, so just line it up with the flats, and put the wrench over the yoke, and on the nut. The nut won't be very tight, so just turn the nut and yoke at the same time.

03-03-2009, 20:20
It should come off w/o a hassle. I use a yoke adapter on my DIN valves and it has worked fine and is probably easier if you do much swapping. Is there a safety reason you don't like adapters?

03-03-2009, 20:31
I keep my regs as DIN for local diving. If I need to jump in the pool with a yoke AL80 (it's happened maybe three times...) or if I were going on a trip where I would only do a few dives on yoke valves, I'd just use an adapter. If, however, I'm going on a longer trip where I'll be diving yoke for the week, I'll convert the regs.

The switch is very easy, but be very aware, it is NOT something you should do often. If you happen to cross-thread the screw, your first stage is trashed.

03-10-2009, 11:39
Thanks to all for the replies. I have the DIN conversion "kit" now (thanks ST!). There is a captive o-ring on the reg-side. Do I need to lube the o-ring before I assemble it to the first stage?

I'm going to take the reg to the hardware store and check out the crescent wrench option, I don't currently have a large enough wrench.

Crimediver: I wasn't really crazy about the idea of using an adapter (safety), but maybe I'm just being too paranoid. Also, I was worried about the reg sitting closer to the back of my head due to the adapter. Maybe I will try one out before deciding to buy one.

BouzoukiJoe A.K.A. wrecker130 AKA Chuck Norris AKA joeforbroke (banned)
03-10-2009, 11:53
When I converted an MR12 reg the yoke nut was very tight. I was afraid I was going to break the reg taking it off.

You might be able to get by without it, but I would recommend lubricating the o-ring to help prevent damge as you tighten the DIN plug.

03-14-2009, 14:35
Almost there. I bought a wide-opening long jaw crescent wrench today. It fits both the nut holding the yoke and also on the DIN part. I got the yoke nut loose without too much trouble. It was pretty tight and there is some kind of thread-locking compound on the threads. I want to be safe and lube the o-ring before I screw down the DIN part, so it'll have to wait until I can get by the LDS and pick up some silicone grease.

04-05-2009, 07:45
Conversion is done. One thing occurred to me, how tight does the DIN part need to be on the first stage to prevent it coming loose during a dive if something applies twisting pressure on the first stage? I've tightened it as tight as I can by hand, using an 8" crescent wrench and holding the first stage in my other hand. Is this tight enough, or do I need to clamp the first stage in a vise to tighten it?

Personally, I can't see it coming loose, but I haven't dived this converted reg yet.

11-01-2009, 18:38
i dont have the torque specs on hand, but it should be tighter then you have it. also the thread locking compound you saw is there for a reason. it is the blue loctite. aply a littlt to the bottom two threads when you attach you yoke or din. it will help with keeping it from comming loose