Intermediate Pressure Low - Scubapro MK10

[Mcarlson]

If the HP cap had backed out, you'd expect IP to rise. As you back the HP seat out, the spring has to undergo more compression to seal, which requires more IP behind the piston head.
Same with seat groove after many cycles. If the shaft has to travel fractionally farther to seat into the newly created groove, once again more spring compression is needed and the resulting IP goes up, not down.
Which seat did you use? Normal (X), Low (||-), or High (|-)??
With normal or low and no shims, I wouldn't be too surprised with a 100 psi IP, though as has been mentioned, it's a touch on the low side.
If it's locks up okay, just shim it up.
Do you have the good red spring?

If you were a little heavy on the lube during the rebuild, piston motion can be a touch sluggish, which allows more time for IP to rise. As the lube wipes clear and the piston movement gets brisker, there is less time for IP to rise before it seals. As a result, the IP drops. That's my best guess for a non-worrisome cause of the problem.

I used the seat that came with the kit I purchased from VDH - so I assume it was a "normal" seat. I'll re-check the seat cap and the torque on the two halves of the body. I rebuilt this one before I had the proper tools so either of those could be off a little bit. It has no leaks anywhere. I just got back from a week in Grand Cayman and I saw it submerged for about 90 minutes each day.

I'm not sure about a "red spring." I rebuilt it with the spring it came with, which had no dye or markings of any kind.

I had assumed that as the o-rings and seat wore out that I would see either leaks or a rise in IP. Are there any other warning signs I should be checking?

 

[Couv]

If the HP cap had backed out, you'd expect IP to rise.

"What we've got here is failure to communicate."

Yes, if the seat retainer (hp cap) had backed out, there would be a rise in IP. (see item 1) However, the OP's reg has experienced a drop in IP after it was initially in specs. SP refers to the part that fits between the body and the swivel as a "swivel cap." (Item17) If this part backs off, it will lower the load on the spring thus reducing IP.

 

[rsingler]

"What we've got here is failure to communicate."
View attachment 452209

Yes, if the seat retainer (hp cap) had backed out, there would be a rise in IP. (see item 1) However, the OP's reg has experienced a drop in IP after it was initially in specs. SP refers to the part that fits between the body and the swivel as a "swivel cap." (Item17) If this part backs off, it will lower the load on the spring thus reducing IP.

View attachment 452213

@couv , this is the SECOND time in a week that I'm misinterpreting things you've explained! I wonder if it has anything to do with the fact that I'm starting to drool?

Now where did I leave my keys?...

 

[Couv]

I wonder if it has anything to do with the fact that I'm starting to drool?

I think you've got more important things demanding your attention. Does she dive?

 

[rsingler]

I think you've got more important things demanding your attention. Does she dive?

She do! Did her referral in Maui just last year (at least I was smart enough not to certify my own fiancee). And Grand Cayman Cobalt Coast together this coming August. Maybe I finally did it right. Thanks for asking, Robert.

 

[Couv]

I'm not sure about a "red spring." I rebuilt it with the spring it came with, which had no dye or markings of any kind.

A while back, ScubaPro started using a different spring. The updated ones were painted red to differentiate the old/new. After all this time your spring has been installed it's very possible the paint has just worn off. If you have the older spring-don't start chasing after a new one until you've at least tried shims and a new seat. In fact, do not remove the seat just yet. Leave it installed, but mark the seat retainer's position relative to the body before removing it and reinstall it in exactly the same position. Check the IP after adding shims but before replacing the seat.

 

[buddhasummer]

@couv , this is the SECOND time in a week that I'm misinterpreting things you've explained! I wonder if it has anything to do with the fact that I'm starting to drool?

Now where did I leave my keys?...

I found my mental abilities started a rapid decline after marriage, my brain become filled trying to remember all the things I should or should not be doing, that could be your problem.

 

[JamesBon92007]

I found my mental abilities started a rapid decline after marriage, my brain become filled trying to remember all the things I should or should not be doing, that could be your problem.

That reminds me:

If a man speaks in a forest, and there is no woman there to hear him, is he still wrong?

 

[lexvil]

That reminds me:

If a man speaks in a forest, and there is no woman there to hear him, is he still wrong?

Yes

 

[lexvil]

I found my mental abilities started a rapid decline after marriage, my brain become filled trying to remember all the things I should or should not be doing, that could be your problem.

No matter what you do or don’t do you’ll be wrong and should have done something else, so don’t worry.