Delta 4 FDX 10 problem

[RIOceanographer]

I just received my Delta 4/FDX10 regulator back from annual service. It worked great before it was serviced. When I tested it on land it seemed to work just as it should, however, I took it on two dives and had some bizarre freeflowing issues. It was a cold dive (39 degrees), so I suppose icing is a possibility, but I've done many dives that cold without a problem using this regulator.

Dive 1 yesterday, I went to about 50 ft. Passing 40 ft or so I started getting a problem where I would inhale, the regulator would properly shut off delivery at the end of the inhalation cycle. However, while I was exhaling the second stage would start to crack open and freeflow more and more as time passed until I inhaled again which reset it. The cycle would then repeat. Tuning the second stage down with the adjustment knob stopped it so I didn't think much of it.

Unfortunately, on the second dive this morning, the issue was worse. I went to 94 ft and by the time I reached that depth both my primary and secondary regulators were having the freeflow issue which suggests to me the first stage intermediate pressure is varying and is the source of the problem. I had to crank the second stage adjustment all the way to maximum to stop it from leaking. Luckily my octo also had an adjustment so I was able to stop it as well. As I got shallower the problem seemed to be less severe. By the time I got it back the parking lot it was acting normally again.

I took it back to the shop and the guy that serviced it was baffled and can't seem to find anything wrong with it. Needless to say that's a bit frustrating.

Any ideas what my be going on or what should be done? Is there some reason the first stage intermediate pressure could be creeping up as a I get deeper?

Thanks

 

[300bar]

Did the shop check the IP

 

[RIOceanographer]

Yes, according to the shop the IP looks fine on the bench.

 

[300bar]

I'm waiting for Oceanic to drop in but I'm thinking along the line of a damaged HP valve.

Or...a miss alinged spring in the HP camber,a missing or miss alinged o-ring in the balancing camber.
Or...

O well lets wait for the master.

 

[RIOceanographer]

Well, supposedly the shop plans to call Oceanic on Monday to try and get to the bottom of this.

He did have one idea which didn't make much sense to me which was that he should have checked the intermediate pressure before he installed the environmental cap rather than after but I wouldn't think that should change anything.

 

[Doug Krause]

There's really not enough information here for me to shed any more light on this - let's see what we find out when your tech talks with our tech.

 

[RIOceanographer]

There's really not enough information here for me to shed any more light on this - let's see what we find out when your tech talks with our tech.

Doug,
Thanks. I understand its difficult to diagnose this stuff via the internet, but I figured it was worth throwing out there just in case there was something obvious he could check for.

As a side note, this shop is not an Oceanic dealer so that may be part of the issue here. The tech said he could handle it, and I am friends with he and shop owner so I chose to let them service it but I am betting this is probably the first FDX-10 he ever did. If the tech can't straighten it out when he calls Oceanic, I'll take it to the nearest authorized Oceanic dealer which is a little out of the way for me but hopefully they'll have a bit more experience dealing with this model.

 

[Doug Krause]

With that last bit of info, I would check your serial number here: Oceanic Worldwide - Scuba and Snorkeling Gear, Scuba and Snorkeling Equipment and Dive Gear

 

[PhilEllis]

You should phone Oceanic customer service and get this regulator to them for a look. Sounds like a "crown"/hard seat issue to me. Of course, as Doug said, determining an exact problem on the internet is difficult, but there are a few clues that might lead to ideas.

Phil Ellis
Discount Scuba Gear at DiveSports.com - Buy Scuba Diving Equipment & Snorkeling Equipment

 

[RIOceanographer]

With that last bit of info, I would check your serial number here: Oceanic Worldwide - Scuba and Snorkeling Gear, Scuba and Snorkeling Equipment and Dive Gear

Thanks Doug, luckily this regulator is newer and outside of that serial number range.

I just spoke to the shop again and they think they got to to the bottom of it. He says when he reassembled the environmental cap he didn't follow the correct procedure.

As he explained it, apparently the first stage should be pressurized with the cap off, the IP should be calibrated, then the regulator should be depressurized before reinstalling the cap. Once the cap is on, the reg should be repressurized and the IP calibration rechecked.

It seems when he did it the first time, he reinstalled the cap with the unit still pressurized after he set the IP and he thinks that caused the unit to be slightly out of calibration. It is a bit surprising to me that this could make that big a difference, but he seems pretty sure of it.

I am getting the regulator back today, so I'll test dive it later in the week (but just in case he still is missing something, I'll be wearing my doubles with a fully redundant first/second stage that I know is in good working order).