Worst-case scenario for unserviced R109

[ericpitar]

Hello people,

Given that I've recently serviced my MK25/r190/R295 reg set 15 dives/1month ago, what is the worst-case scenario in open water if I replaced my R295 with a recently-acquired but used R109 reg that was not serviced but appears to function fine in a pool?

A veteran diver advised "if it ain't broke, don't fix it" and that the worst would be a freeflow which would still give me the R190 as backup anyway.

Any feedback/comments?

E

 

[Packhorse]

Worse case?
It free flows, you loose all your air and panic. you rush for the surface holding your breath and have an embolisim. Your buddy follows you and suffers the same fate. Divers on the same boat jump in to save you both but are attacked by a group of sharks attracted by the blood leaching from your lungs. A shark bites thru a tank and the valve snaps off sending the tank thru the hull of the boat causing it to sink killing everyone on board. One of which was the only man who could stop a world wide out break of SARS.

But thats pretty unlikely.

 

[ericpitar]

I'm red with laughter but that's excellent feedback!! thanks for your input!

 

[Packhorse]

I just brought my second 109 (not R109 by the way) and threw in a spring and G250 service kit converting it to a 156 and I cant wait to try it out tomorrow!!

 

[halocline]

If you tried it in the pool with the same first stage, it'll almost certainly work fine. You might have a close look at the hose fittings, make sure both hose o-rings are okay (replace them if you have any doubt) and then make sure it holds a vacuum by attaching it to the 1st stage, putting it on a tank with the air off (or tight dust cap) and drawing on the mouthpiece with some effort. If you can pull in any air it's going to leak.

Those regs are pretty tough.

 

[Couv]

Well said Packhorse, I was thinking the exact same thing. ;-)

I would have a hard time coming up with a worst case than he described. But, more than likely the greatest disappointment you'll suffer will take place when you realize that your vintage, used, bargain regulator works just as well or better than the plastic POS you paid a lot of money for. Throw less dry mouth into the deal and you just may end up with bi-polar disease.

Seriously, in addition to what Matt has said, do a good overall inspection including checking the hose is torqued down correctly at both ends. Examine all the accessible rubber parts for dry rot. No big problem if the exhaust Tee is a bit shabby, but the mouth piece and diaphragm cover should be in good shape. Check the hose for signs of cracking or splitting. If you had it in the pool, then I'll take for granted you did a bubble check.

Congratulations on a good buy.

c

 

[ericpitar]

Upon closer examination, I noticed a couple of 5mm long cracks on the top part of the exhause tee when squeezing the tee a bit. Anyone have any recommendation on what to do with this? I was thinking of putting a drop of crazy glue on the crack to keep it from enlarging but I'm afraid this might worsen the integrity of the rubber. Anyone have inputs?

 

[redacted]

Leaks and/or poor performance.

Many 109s have spent a long time in storage before they show up in the used reg market. I would expect the orifice o-ring to be pretty old although I have seen some that looked more like plastic than rubber and still sealed. More likely the LP seat is engraved and hard resulting in poor performance at best and likely a slight leak. Cranking down on the adjuster may stop it but will further reduce performance. Older exhaust valves were not of the same material as modern versions and should be expected to leak water in resulting in wet (maybe real wet) breathing.

If you put it on a tank and it breaths well with no leaks, it may well be OK. But it really is a very simple reg to service and a good place to start DIY. The 109 poppet has gone through a number of upgrades. If yours has a fixed seat, either riveted or bonded directly to the poppet, it really should be upgrades and the rest of the reg serviced (2 new o-rings and a critical look at the exhaust valve). If it is one of the newer poppets that takes the replaceable hockey puck style LP seat, then it may well be usable with just cleaning and lube (since you are there anyway).

Another possibility is that it has already been upgraded to a Balanced Adjustable. You will need to remove the clip and the adjustment knob and then dump out either a spring pad and a heavy spring or a balance chamber and a light spring to tell. You will need to do this anyway to know what kind of service kit to look for. If it is upgraded already, then peek down the barrel at the balanced poppet stem. If it is metal (shiny stainless steel) , it is one of the older versions and probably needs to be replaced. If it is white plastic then it is a newer version and again may be OK for a while.

Edit: New exhaust-Ts may be hard to come by so if you have one that is marginal, I'd start looking for a replacement right away. The dry-rot on the exhaust-T is an indication of long storage in unfavorable conditions. I can't see where a little rubber cement on the cracks can hurt and it should slow the deodorization process that will eventually retire that exhaust-T. Plus, if it is bad, you will need to take a good look at the diaphragm and rubber cover. The diaphragm is easy to find but the rubber cover is another part discontinued by Scubapro and real hard to come by so treat it gently.

 

[halocline]

You might get some aquaseal for the exhaust tee. I've used it to fix tiny cracks in a D300 purge cover and it worked well. Just open the crack a little, work some aquaseal into it and release so the crack closes up filled with aquaseal. It should last a long time, which you will need to find a new exhaust tee.

I was going to also recommend some DIY service, but that's up to you. Once it's upgraded to balanced/adjustable and in good tune you'll have a very tough time finding a reg that breathes better at any price.

 

[Couv]

I'm going to go against the Usual Suspects here on the exhaust tee. If it is just the tee that is bad, it should be ok for use. But, yes look for a replacement...do not remove it until you have one as it will probably disintegrate. If it does not disintegrate, it will be very hard to re-install and you will cuss us endlessly. If there are just some slight tears in the rubber, take a hot pin and "stop drill" each end of the tear or crack. This will divide the stress over a larger area and prevent propagation of the crack. I would not waste Super Glue or Aquaseal on the exhaust tee; most likely it will not help and may hide the tear.

c