Old ScubaPro R109 2nd stage

[aquaregia]

So I've got these two 109s open on my desk. I think I cleared up the stuck adjustment knob, and the other one I think just needs a new exhaust valve. Gonna start the LDS circuit tomorrow.

There are a couple differences between these. So one of them (the stuck knob one) is basically beautiful on the inside. Smooth and shiny on the inside with no sign of any pitting or corrosion. The seat seems to reside inside the end of the poppet, and the inside end of the poppet has a nice round top to it where the spring sits. The spring pad has some crap on it where it's attached to the knob (vaseline perhaps) which forms a light adhesion. The diaphragm disc is plastic. The blue o-ring and exhaust valve look very pretty. There's no sign of the red o-ring. The screws have an allen head.

The second one (which I think is older because it's attached to the 2port Mk5 not the 5port Mk5) has some light scarring on the inside, some green oxidation is present. The seat is separate from the poppet, and the poppet has four spires each with an indentation for the spring to sit in. The blue o-ring is black, but other than that looks fine. No visible cracks or discoloration. The diaphragm disc is metal. The exhaust valve is useless. I blew in one end of the tee with my hand over the other end, and my breath flowed backwards through the valve very easily. There's no sign of the red o-ring. The screws have a phillips head.

What's my next step towards calling these "serviced" (albeit amateurely)? Naturally, replace the exhaust valve in the older one and clean out the inside a bit (vinegar's the trick?). Apart from that, how nice does the seat need to look? Both of the seats have fairly convincing circular indentations, presumably from the spring pushing it against the orifice. What's the tolerance on this? Finally, what should I use for lubrication of o-rings when I put it back together?

Thanks for all the help. I was surprised how few parts were in this when I took it apart. I definitely spent five minutes trying to figure out how these could possibly work.

 

[Zung]

Congrats for a successful part 1! Here's your todo for part 2:

Cleaning:
Reg #1: warm water, detergent (dish washing stuff), old tooth brush; carefully examine all o-rings see if there's any hope left: round, no nicks
Reg #2: 5' in white vinegar, then proceed as #1. The green stuff should go away; if not, repeat

Lubing:
Ideally, Christo-Lube or equivalent (27 bucks). Else silicon grease if you're not into EAN (what's this for?). Lube the threads of the adjustment knob.

Testing:
If the 1st stages are good (are they?), reassemble reg #1 back (don't over tighten anything, most likely you're gonna open it up again), connect air, tune the orifice as described here many times over (screw in while holding down the purge until freeflow stops), check for leaks, attempt to breath, immerse 2nd in water diaphragm down and mesure cracking pressure (roughly the distance between the middle of the cover to where it starts flowing). This is to see if there's any hope left in the seat.

Shopping list:
- Seats
- Exhaust valve
- O-rings

Good luck and keep us posted!

 

[Texfrazer]

Congrats!

If you can't find seats, there's a little trick from couv or awap (sorry guys, I can't remember which one gave out this little gem) about making your own. It's easy. A quick order of a sheet of epdm and a specific sized punch (both obtainable from McMaster Carr) and you are good to go!

 

[halocline]

The first one sounds like it has the current unbalanced poppet. You can carefully remove the seat from that and flip it over, or you can get a new seat. The seat is for the G200, R190, R295, etc. You can also find those seats in the trident catalog, or you can make them as described.

The second one sounds like it has the original poppet, so you'll need to replace that with either one just like the one in the first reg, or with the s-wing G250 poppet, balance chamber, and spring, making it a balanced reg. Since you're buying these parts new (I presume) I would suggest going the balanced route; it's a little more money, but then you'll have one balanced and one unbalanced and you too can experience how subtle the difference is.

In both cases you'll want to remove the orifice by unscrewing from the barrel where the hose was connected and pushing it out from the other end with a plastic or wood tool, I use a chopstick. Then you can check it's edge for nicks, clean it, and try a new 010 o-ring on it. The red SP o-ring is a slightly different size, but the 010 has always worked fine for me.

I'd replace the o-ring on the adjustment knob, I think it's a 011. Amazingly enough, those are the only two o-rings in the unbalanced reg, the balanced one has 2 tiny o-rings on the balance chamber. Heavily lube the threads of the adjustment knob, those really get stuck as you know.

If you want you can replace the original diaphragm (the metal pad) with a current G250 diaphragm, but unless there are pin holes or obvious signs of wear, it's not necessary.

 

[redacted]

So I've got these two 109s open on my desk. I think I cleared up the stuck adjustment knob, and the other one I think just needs a new exhaust valve. Gonna start the LDS circuit tomorrow.

There are a couple differences between these. So one of them (the stuck knob one) is basically beautiful on the inside. Smooth and shiny on the inside with no sign of any pitting or corrosion. The seat seems to reside inside the end of the poppet, and the inside end of the poppet has a nice round top to it where the spring sits. The spring pad has some crap on it where it's attached to the knob (vaseline perhaps) which forms a light adhesion. The diaphragm disc is plastic. The blue o-ring and exhaust valve look very pretty. There's no sign of the red o-ring. The screws have an allen head.

The second one (which I think is older because it's attached to the 2port Mk5 not the 5port Mk5) has some light scarring on the inside, some green oxidation is present. The seat is separate from the poppet, and the poppet has four spires each with an indentation for the spring to sit in. The blue o-ring is black, but other than that looks fine. No visible cracks or discoloration. The diaphragm disc is metal. The exhaust valve is useless. I blew in one end of the tee with my hand over the other end, and my breath flowed backwards through the valve very easily. There's no sign of the red o-ring. The screws have a phillips head.

What's my next step towards calling these "serviced" (albeit amateurely)? Naturally, replace the exhaust valve in the older one and clean out the inside a bit (vinegar's the trick?). Apart from that, how nice does the seat need to look? Both of the seats have fairly convincing circular indentations, presumably from the spring pushing it against the orifice. What's the tolerance on this? Finally, what should I use for lubrication of o-rings when I put it back together?

Thanks for all the help. I was surprised how few parts were in this when I took it apart. I definitely spent five minutes trying to figure out how these could possibly work.

The red o-ring is on the orifice which you will want to carefully remove for cleaning. It is a -902 which is just a hair thinner than a -010. The -010 may work as a replacement but may be too tight. After unscrewing the orifice, you will need to push it out with something that will not damage the knife edge. I use a long rubber erasure. Handle it very carefully as one oops will cost $10 to $25 depending on plastic or metal.

Sounds like the first 109 has the modern duro poppet which takes the replaceable seat. You shou8ld ba able to lift it out with a fingernail (or straight pick from the side if the fingernail fails). The seat can be flipped if the other side has not already been used. Some tech may have applied a little glue that will make it harder to remove. Glue is unnecessary. The seat will stay in place without it. The "crap" is most likely a more than generous application of silicon grease.

The second one sounds like the older poppet but I have never been able to seperate the poppet from the seat. The seat is attached to the end of the poppet. As a temporary measure, I have sanded the groove out of those seats just to make sure everything was working while I went shopping for a Duro poppet. The "green oxidation" (verdigris) is fairly easily removed with a light acid (50/50 vinegar and hot water) bath. 5 to 10 minutes or 2 to 3 minutes in an ultrasonic cleaner. Wash in detergent first to remove all grease and oils. After the bath, rinse in a neutralizing solutio (baking powder and water), then rinse in hot water, dry, and inspect. If you still see green that you want to remove, repeat. But don't overdue it as it will also remove chrome and reveal the copper or brass underlayer. Scubapro stopped using colored o-rings around 2000 so the black o-ring on the adjuster suggests aftermarket o-rings or a leak repair without updating the poppet.

For lubricant, you should use Tribolube or Christolube which are O2 compatible for use with nitrox. Grooves are undesirable in the seats. The deeper the groove, the more performance will be degraded. I make my own LP seats (http://www.scubaboard.com/forums/re...85694-scubapro-r190-r380-r390-nylock-nut.html) but I am also looking for an aftermarket source for those seats for the less adventuresome. I'm waiting on a delivery of aftermarket HP and LP seats that hopefully will work with MK2/5/7/10 1st stages and balanced and unbalanced SP 2nds.

 

[Zung]

... I'm waiting on a delivery of aftermarket HP and LP seats that hopefully will work with MK2/5/7/10 1st stages and balanced and unbalanced SP 2nds.

awap, if ever you want to setup a group buy, please count me in
Over here, the original seats are orderable at a cost: G-250: $7.60, R-190: $4.45

 

[Texfrazer]

I'm waiting on a delivery of aftermarket HP and LP seats that hopefully will work with MK2/5/7/10 1st stages and balanced and unbalanced SP 2nds.

awap, if ever you want to setup a group buy, please count me in
Over here, the original seats are orderable at a cost: G-250: $7.60, R-190: $4.45

I'm in for the HP seats and possibly the balanced LP seats.

 

[redacted]

awap, if ever you want to setup a group buy, please count me in
Over here, the original seats are orderable at a cost: G-250: $7.60, R-190: $4.45

If this works out, I'll advertise the shop that will support us.

Those costs are really bad. Last time I purchased G250 seats, I believe I paid $2.50 each and that was with a 100% markup over dealer cost. But that was before the most recent price increase by Scubapro. I took to making my own hockey puck (R190 et al) seats over a year ago. They cost me a little under $.01 each for material.

 

[aquaregia]

I flipped the seat in the newer one, but it looked like it had some adhesive on it before. Or was that just gook from the seat under pressure?

 

[aquaregia]

I hadn't considered doing my own O2 cleaning. Is that easy/safe?