Yoke to din change out on Scubapro reg

[JBRES1]

I purchased a few MK2+ 1 st stage regs from Scubatoys last week, and now I want to change out one of the yokes to a din connection that i have.
Looking at the reg I don't see any way for me to get a wrench into ther yoke to back out the nut.
Do I need a special tool to do this change out , or a very thin socket ?
Thanks, Jim Breslin

 

[Hoosier]

Yes, you need to have a thin 1 inch socket. Otherwise, it leaves many scratches on the Yoke fitting...

Just bring it to any LDS and ask un-screwing a yoke fitting.... That is the most simple and easiest way to do for your life. It doesn't have to be SP dealer.....

Happy New Year!

 

[DA Aquamaster]

Most yokes are designed in such a way that a thin walled yoke nut socket needs to be used to remove the retaining nut. In a pinch you could use a very large cresent wrench (15 inches or larger) but it will only contact 2 flats on the nut and if it is stuck or over torqued you could damage the nut while removing it. Over torquing of these nuts is also depressingly common on regs that have had a DIY service and the addition of a little corrosion can make them very hard to remove.

You will also need a long reach 6mm hex socket to allow the retainer to be properly torqued to 22 ft pounds. Unless you have the yoke nut socket, hex socket and torque wrench already, it is a lot more cost efficient to have the LDS make the change.

 

[JBRES1]

Well all I'm missing is the thin wall socket.
I put a vernier caliper on the nut and it looks to be 15/16" not 1" as noted earlier.
I may just cut down a socket and then turn its outside diameter down to fit.
Jim Breslin

 

[DA Aquamaster]

I currently have a range of SP first stages spanning about 30 years of production in front of me and all of them have a 1" retainer nut. I have never seen an SP first stage with a 15/16" yoke retainer nut.

 

[cool_hardware52]

I've removed SP yokes using a bench vice. It's possible to grip the nut in the jaws by inserting the the yoke into the vice "yoke down"

This is superior to a large cresent wrench in that you can actually clamp the vice tightly to the flats on the 1" nut.

It's very likely you will scratch the yoke, but if you are permanetly changing to DIN you may not care.

If you lack the tools and torque wrench (and know how to use it) you are better off in the hands of a pro.


Tobin

Good luck

 

[redacted]

My photo gallery has a couple pics of homemade yoke nut sockets. It is a 1" socket. But you will need a good vise to hold that Mk2 and a torque wrench to measure the 22 ft-lb when you install the DIN connector (or swap it back to the yoke).

 

[JBRES1]

You guy/girls are great.
Mission accomplished.
I took the advise of placing the yoke nut in a vise and un-screwing it, worked like a charm.
The pics of the 1" socket would have worked if I went that route, but didn't need to.
I torqued down the din connection to 22 ft lbs, hooked up a gauge and 2nd stage and put it on a tank and it worked just fine.

Thanks again for the help, I know why this board is so great . Its the people like yourselves that come here and are more than happy to help out where you can.

Jim Breslin

 

[DA Aquamaster]

But you will need a good vise to hold that Mk2 and a torque wrench to measure the 22 ft-lb when you install the DIN connector (or swap it back to the yoke).

This is (believe it or not) an SP approved procedure, but in the abscence of a padded vice, you can screw a first stage wrench into one of the LP or HP ports on a Mk 2 to act as a lever, then place it on the floor and hold it down with your foot while you apply the 22 ft pounds of torque on the yoke nut. Obviously the first stage wrench has to be screwed into a port that allows you to turn the yoke nut the right way wedging the wrench against the floor.

The first stage wrench serves the same function in a padded vice preventing the first stage from rotating while you apply torque to it.

On L shaped first stages such as the Mk 5, Mk 10, Mk 15, Mk 20, Mk 25, etc, you can do the same thing by placing the reg on the floor (carpet is obviuosly beneficial here) so that the long end of the reg prevents it from turning while you apply torque. Foot pressure on the first stage will keep the first stage flat against the floor while you apply pressure to it. You do not ever want to put a first stage wrench into the LP ports in the swivel cap, and especially the one on the end of the swivel cap while doing this as you can snap the swivel cap retaining nut doing this as it was not designed to take those types of loads.

And of course in a pinch, a threaded CO2 cartridge fits the 3/8" LP ports and can serve as a first stage wrench (although I recommend you only do this with expended CO2 cartridges.)