Scubapro S550 sticking on 1st exhale

[rcs9250]

I've read in one of my repair manuals (Mares?) specifically not to do this. They mention not getting silicone grease on the diaphragm or exhaust valve. I think the bigger concern is the diaphragm slipping; I'd think the exhaust valve due to it's design is less likely to slip....

I think just cleaning as awap described is the best bet.

For what it is worth, I've had several regs do it. I believe that it is just a little impurity (salt, whatever) on the edge of the valve that does not wash off when you soak the reg after use (because the exhaust valve is sealed, and its edge traps the salt). When it dries, it gets "sticky" until the 1st exhale, then all is good.

Not a big deal, just annoying.

Best wishes

I dive freswater pretty much exclusively (999 out of a 1000 ) so salt isn't the issue. Not exactly sure what the issue is but it really is just the Apeks's in my case. Sounds like a materials issue. Regardless it is not a big deal.
My regs get a thorough hand washing of the exhaust diaphragm during rebuild and they (Apeks) still do it.
DA Aquamaster. You are right on the silicone and diaphragm expanding. I have some old regs that I use for classes that are cutaways that I am going to lube up and see what happens. I think it's Ikelite that provides a proprietary silicone for their O rings on there camera housings. Whether it's special or not would be up to a chemist to comment on . What is for sure though is that they know there compound won't affect the O ring.

 

[DA Aquamaster]

DA Aquamaster. You are right on the silicone and diaphragm expanding. I have some old regs that I use for classes that are cutaways that I am going to lube up and see what happens. I think it's Ikelite that provides a proprietary silicone for their O rings on there camera housings. Whether it's special or not would be up to a chemist to comment on . What is for sure though is that they know there compound won't affect the O ring.

Way back in the '80's when I first started DIY reg repair, the shop that did my service work before then replaced the diaphragms annually and returned the old ones. That was about the same time they switched from rubber to silicone. So...not knowing the difference and figuring that a little silicone lube as a preservative could not hurt, I sprayed them all down and stored them in a zip lock. The end result is that when I finally needed them, they were all a bit too large in diameter and had about an extra 3/16" inch of circumference that had to be dealt with to get them to seat properly. Major PITA and I have never done that since.