HenrikBP
Contributor
So I've finally worked up the courage to rebuild one, maybe two late-model SP MK5 regulators and of course have a few questions ...
I have read both regulator rebuilders "bibles" and have exploded diagrams of both MK5 and MK10, including Couv's excellent MK10 diagram with std. o-ring size annotations, as well as the service manual for the Oceanic PX2 - an MK5 clone I believe. Thanks Couv!
1) does anyone have an annotated diagram of the MK5 o-rings similar to Couv's MK10 diagram?
The 2 regs are similar on the outside with 2 x std. size HP ports and 5 std. size LP ports.
I have the 2 regs apart and all parts cleaned and noticed some differences in the internals.
2) One piston shaft is very slim and light, the other one has a fairly thick and solid base. Which one is the newer version, and which one would provide the best performance - not that I expect there to be a big difference, just curious?
3) One reg has a new version yoke retainer that takes a cone shaped filter, the other is an older version that takes the flat filter. My LDS can't even get the cone shaped filter except in full rebuild-kit form. Can the flat filters be found anymore?
4) if no flat filters, what are the odds of finding a "universal" yoke retainer that will work with an MK5?
5) I have an MK10 that whistles with each breath, and I know from the excellent contributors here on SB that it is usually due to lack of lubrication of the piston shaft HP o-ring and that o-ring durometer could be a contributing factor. So might a size -010 85-durometer viton o-ring help prevent whistling? (Viton just because it's what I happen to have on hand - not due to any O2 compatibility concerns).
6) I got a DIN connector along with one of these MK5 regs. eBay seller said it was for the MK5, but it is the newer version that seals at the bottom. I've read the threads here about these - that they won't work, especially not with the MK5 saddle. But it looks like it might work without the saddle and with an o-ring at the top of the threads. I seem to remember someone trying, but can't find the thread - so will it work?
7) of the 2 turret retaining bolts, one has a few nicks and in the nicks it looks like it's brass under the chrome. The other one is spotless. None of them are magnetic. Other than scratching the spotless one as suggested in the MK5 service diagrams, is there a way to determine if it is stainless or brass?
8) Any word on a new batch of SS turret bolts?
9) How about these torque specs? for the turret bolt: 100 - 120 in/lbs? For the yoke retainer: 23 - 25 ft/lbs? For the DIN "retainer": 16 - 18 ft/lbs?
10) I'm guessing the seat retainer cap and the ambient chamber get screwed in place just tight enough to stay in place?
11) One reg had no plastic spacers in the ambient chamber, the other had 2 in white/clear plastic - very thin. Are these spacers there to adjust IP or are they just to keep the steel spring off the chrome in the ambient chamber?
I'm sure I'll have more questions, but I'll stop for now
Thanks in advance,
Henrik
I have read both regulator rebuilders "bibles" and have exploded diagrams of both MK5 and MK10, including Couv's excellent MK10 diagram with std. o-ring size annotations, as well as the service manual for the Oceanic PX2 - an MK5 clone I believe. Thanks Couv!
1) does anyone have an annotated diagram of the MK5 o-rings similar to Couv's MK10 diagram?
The 2 regs are similar on the outside with 2 x std. size HP ports and 5 std. size LP ports.
I have the 2 regs apart and all parts cleaned and noticed some differences in the internals.
2) One piston shaft is very slim and light, the other one has a fairly thick and solid base. Which one is the newer version, and which one would provide the best performance - not that I expect there to be a big difference, just curious?
3) One reg has a new version yoke retainer that takes a cone shaped filter, the other is an older version that takes the flat filter. My LDS can't even get the cone shaped filter except in full rebuild-kit form. Can the flat filters be found anymore?
4) if no flat filters, what are the odds of finding a "universal" yoke retainer that will work with an MK5?
5) I have an MK10 that whistles with each breath, and I know from the excellent contributors here on SB that it is usually due to lack of lubrication of the piston shaft HP o-ring and that o-ring durometer could be a contributing factor. So might a size -010 85-durometer viton o-ring help prevent whistling? (Viton just because it's what I happen to have on hand - not due to any O2 compatibility concerns).
6) I got a DIN connector along with one of these MK5 regs. eBay seller said it was for the MK5, but it is the newer version that seals at the bottom. I've read the threads here about these - that they won't work, especially not with the MK5 saddle. But it looks like it might work without the saddle and with an o-ring at the top of the threads. I seem to remember someone trying, but can't find the thread - so will it work?
7) of the 2 turret retaining bolts, one has a few nicks and in the nicks it looks like it's brass under the chrome. The other one is spotless. None of them are magnetic. Other than scratching the spotless one as suggested in the MK5 service diagrams, is there a way to determine if it is stainless or brass?
8) Any word on a new batch of SS turret bolts?
9) How about these torque specs? for the turret bolt: 100 - 120 in/lbs? For the yoke retainer: 23 - 25 ft/lbs? For the DIN "retainer": 16 - 18 ft/lbs?
10) I'm guessing the seat retainer cap and the ambient chamber get screwed in place just tight enough to stay in place?
11) One reg had no plastic spacers in the ambient chamber, the other had 2 in white/clear plastic - very thin. Are these spacers there to adjust IP or are they just to keep the steel spring off the chrome in the ambient chamber?
I'm sure I'll have more questions, but I'll stop for now
Thanks in advance,
Henrik
Last edited:
About time I got some use of all the scuba tools I bought.
