Royal Aqua-Master Overhaul

[Bryan]

Pictured below is Ole Number 7, battle axe of all my regulators. All reproduction parts for the DA series gets tried out in this beauty before they go any further. After diving the 1st day at Lake Wazee I developed a hole in one of my favorite tight accordion original hoses. Unfortunately this happened when I loaned the regulator to Jerry Mossman after bragging to him how well it breathed! Sorry Jerry! So when I got home I decided to give it a good going over.
I am not saying this is the only way to do it……Nor am I recommending that you do it at all…….I’m simply sharing some of the steps I use in refurbishing Royal Aqua-Masters. There is an Excellent copy of the US Divers factory repair manual for the Royal in the downloads section of my main site. As we go through this please feel free to comment and ask questions.
1st you need a few things to get it done right. A basic set of good hand tools including open end and Allen wrenches. Don’t use cheap or worn out tools! You will screw up your regulator and could possibly damage expensive parts.
2nd you need a few other parts and tools to do the job right. A parts kit, intermediate pressure gauge, regulator cleaner and if you are going to do a lot of regulator work I highly recommend a high pressure nozzle assembly tool that is made by our own Tom (Captain) Madere.

Lay the regulator on a flat surface and start taking it apart. Use the manual as your guide. Do it SLOWLY so you can remember the way the parts go back together. Take digital pics so you can review each step you do. Remember to disassemble the high pressure diaphragm and nozzle assembly carefully as they are under spring tension. Parts could go everywhere! (don’t ask how I know this….)
When the regulator is completely apart I soak all of the metal parts for a few hours in regulator cleaner. It’s the best stuff I have found for taking off years of salt water corrosion and other crap that gets on these regulators. Follow the directions...don’t soak your painted label in this stuff, it might fade them. Other cleaners I have used with some degree of success are Simple Green and household vinegar.

[Bryan]

After your parts have soaked for an hour take a few of them out and see if they clean yet. If not, try scrubbing the stubborn spots with a nylon brush. Until the parts are completely clean there is no sense in going any further.
Once all parts are clean and dry it is time to inspect them. The LP seat and stem is the place I usually start. Remove the old black seat and discard it. Nothing ruins the fine tuning of a regulator like a hard LP seat. Inspect the area of the stem where the seat goes. Remove all traces of previous adhesive and clean out the weep hole at the bottom with a pin or sharp pick. This hole must be clear so any excess adhesive can pass through when the new seat is installed.
NOTE, When these regulators were new the brass nut that adjusts the 2nd stage lever was staked and often cemented in place on the threads of the stem to keep it from moving. During the rebuild process the tech would simply cut the brass nut off and discard the stem. We don’t have that luxury these days so take your time and clean the threads as thoroughly as possible. Try the new brass nut and make sure it moves freely with no binding. If it binds clean the threads until it stops binding. If the nut cannot move freely on the full length of the stem it will cause the stem to turn at the same time you are trying to adjust the nut. If this happens you will never get your 2nd stage lever height set correctly and you will cut a nice groove in your new LP seat and destroy it.
Now you are ready to install the new LP seat. Put a small amount of neoprene cement in the bottom of the stem. Use it sparingly! Too much and it will get all over the top side of the LP seat when you push it back in place and it will be ruined. One good drop in the center and spread it around the inside with a toothpick should do the trick. Put your new LP seat in place and push it down tightly with your thumb. Wipe off any excess cement that comes out of the weep hole at the bottom and make sure no cement has come in contact with the surface. Set it aside to dry.

[Bryan]

And you thought rebuilding a double hose was quick and easy……..

The main body of the regulator requires some attention to detail. Especially the passage that connects the low pressure side of the diaphragm that runs to the hookah port and nozzle for the low pressure seat assembly. This area is usually full of 40 or 50 years of buildup that you want NO WHERE near your mouth or lungs! The soaking of your regulator parts in cleaner should have loosened it up. I suggest running a cotton swab through this passage as many times as it takes till the cotton swab comes out on the other side looking as clean as it did when you took it out of the package. You will be surprised on how dirty that area can be. Do the same thing for the nozzle opening where the LP seat and stem sets. DO NOT use a hard or pointed object. If you damage the seating area in the nozzle where the LP seat rests you can throw the body away. Or make a paperweight out of it. Cotton swabs and patience are all that is needed to get this area clean. Take time to look at all the threads……There are a lot of them on the regulator body. They need to be clean and free from any debris. Here is where a nylon brush and a brass pick come in handy. Be careful with the pick. It should only be used when you cannot remove the debris by soaking or brushing. Finally take a look at the backside of the regulator body. The gasket seating surface where the nozzle screws into the body must be clean and smooth. Despite what you may have heard, the nozzle to body gasket SHOULD NOT be re-used. The gasket is made from phenolic material and easily damaged or broken. After you are satisfied that the regulator body is clean I would give the whole thing a good bath in antibacterial soap and set it aside to dry.

[Bryan]

High pressure nozzle

The Royal Aqua-Master 1st stage is balanced so most of the parts are unique to the Royal only. The Conshelf series of regulators has the same 1st stage to this day as the original Royal Master. 99% of the parts that go in the current regulators 1st stage will fit in the Royal series of double hose. With minor modifications all of the parts will work and it does improve the performance of the regulator in my opinion. Back to the regulator at hand…..
The nozzle assembly must be absolutely as clean as possible! There are a lot of small holes and grooves that you can spend plenty of time on with a cotton swab and a toothpick. Be very very careful of the cone (volcano hole as Luis calls it) inside the nozzle where the HP seat sets. If you damage it the nozzle is ruined….
Next take a look at your high pressure seat and make sure it is clean and there is no debris in the passage through the body. Many a fool has tried to plug this passage with glue, solder, JB Weld etc in an effort to use them in the DA series of regulator…IT WILL NOT WORK….It may hold for a while but I will bet some big coin that it will fail and the results will be disastrous!!! I digress….The surface of the Royal HP seat is a hard rubber and in my estimation you cannot resurface it at all. I have seen very few of them go bad though. The latest Conshelf HP seat has a blue Teflon seating surface and work really well and is tough as nails!
Take a look at the inside of the crown and make sure it is clean and install a new O-ring. This area seems to gather debris very easily so clean it thoroughly. When you are finished take the SLIGHTEST bit of silicone on a cotton swab and put it on the O-ring. If you can see the lubricant you have put too much on. What we are trying to accomplish is to let the HP seat stem slide easily into the crown when it is compressed during reassembly.
You should be ready to assemble the 1st stage now. Follow the instructions in the USD manual for assembly. This is when the HP nozzle assembly tool comes in handy.