Strange purge cover ono 109

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elan

Contributor
Messages
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Location
Toronto, Ontario, Canada
# of dives
200 - 499
I have got a 109 on one of the well known websites :) The guy told me that it was freshly rebuild and "Tested by a diving instructor" ( I love those statements ) :)

After examining the patient it was noted that it beautifully cranks at lovely 2.5 inches at the easiest settings.

After cleaning (it looked like it was literally lubricated with machine oil :)) I examined the orifice and have not found anything wrong. I have noticed that the lever height seemed to be too high. Comparing it to another lever and trying to put the diaphragm back on proved that it is indeed too high. Replacing the lever made the reg cranking around 1.1-1.2 which seemed very reasonable. But... After putting the purge cover on the reg started free-flowing badly. Examining the cover revealed that there is a kind of pretty high (about 3 mil) border surrounding the insignia and that border pushes on the diaphragm when the cover is installed. The guy who have rebuilt the reg apparently compensated for this flow with screwing the orifice further in and thus the initial cranking sucked.

I removed that excess rubber and now the regs gives me the same 1.1-1.2 but that makes me wonder whether that was an original SP cover or it was some kind of aftermarket. It had 5 holes in it.

I have some VDH covers but they are different and have no rubber in that area.
 
You might have had a 108 cover on there. It's meant for the 108 diaphragms that are shaped differently. Too bad you removed the rubber as those are hard to find. Zung was kind enough to send me one for my 108 and it made all the difference.

When I first started diving I bought a professionally serviced 109 that had a USD diaphragm and another professionally serviced G250 with only the tiny remains of an o-ring in the venturi assist vane. It's really quite something how professional some of these professionals are.
 
I guess you are right. Its good I have no 108s in my stable so no huge regrets :)

The only regs that I was receiving properly serviced were coming from bigfoot-daisy and you. With the rest I was always happy that I had opened them :)

BTW: Mk5 in 37F yesterday, no hassles, not sealed :) I will see how far it will go.
 
Yes, the strange fellow is legit; it's for the older 108's and it should look like that:

109-Cover-SP.jpg


It goes with this diaphragm:

108-Diaphragm-Top.jpg

Too bad you trimmed it, I'm sure halo could use a spare. :)
 
I have one of those old 108 diaphragms in my spare parts and had no clue what it was. Who need it?
 

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