Mk25/A700 breathing trouble

[Nick Ruberg]

Hi guys,
I am hoping for some explanation. I have noticed ove the last two weekends when using my Mk25/A700 combination that during the initial stages of a dive when having students at a 5m grid I felt as if I was sucking a golf ball through hose. Strangely, later on I don't know if I got used to it or if it improved.

diving today was the same, however I seem to notice that it got easier and at that stage I could either hear or feel the cracking pressure. It felt as though wheni inhaled, there was a brief period of resistance and the. A valve cracked open and I got a rush of air, so you get this feeling of sucking-nothing, suckin-nothing, then suddenly whoosh.

Altitude was 1150m above sea level and water temp 17 deg. C. I can't remember having this in the past (not to say it didn't happen, just that it doesn't stick in my mind).
Thanks,
nick

 

[JulesSCUBAPRO]

Verify that the tank valve was completely open as this can explain the symptoms you've described. If this is not the case, take the regualtor to an authorized dealer for evaluation.

 

[herman]

That is not a closed valve, symptoms of that are the opposite of what he describes besides, hopefully an instructor (guessing on that since he does say with students) would not miss opening a valve fully on multiple occasions.
My best guess is hardened (cold) lube that is softening up with use...time to have the reg serviced.

Welcome to the board.

 

[Nick Ruberg]

Thanks for the reply. I am a DM candidate and was watching an instructor/supervising. Valve was definitely open or otherwise it would not get better. I wondered about cold, which is why I posted the temp, but surely 17 deg. Cannot be considered cold.

i sent it in and will advise what SP says.

 

[herman]

It's not really bad cold but it is cold enough to cause defective grease to harden. As the reg works it warms and loosens the grease. My bet is it would be resolved with a good service.

 

[Nick Ruberg]

Sorry for the late reply, but here goes.

i sent it in to SP and they did not find anything out of the ordinary, but they serviced the reg anyway (and in record time so that I could dive the next weekend - Scubapro here in SA has the BEST service).

after the service and despite them stating they found nothing wrong! it has been breathing like a dream.

thanks for all the input.
nick