Malfunctioning inflator - can't find the defect

So, a couple of dives after I serviced and replaced the o-rings on my inflator, it got stuck and free-flowed, sending me up like a cork. I wasn't too concerned since it had been a shallow dive and I was at 26 feet when it happened. I reacted by depressing the dump button, thinking it would stop the ascent. It didn't. Interesting lesson. Of course, what I SHOULD have done is simply disconnect. Duh. Next time.

I went back down and completed the dive inflating my wing orally, and disassembled the inflator back on the boat. Couldn't find anything wrong with it. After that, it seemed to work fine, until sometime during the next dive, I depressed the inflator button and nothing happened. Tank pressure was 2,000 psi or something like that. I worked the button a bit, and finally air started flowing. Except it wouldn't stop, again. This time, it was more a trickle than a rush, though. I disconnected the hose and completed the dive.

I'm diving Deep Sea Supply wings, which use a generic inflator, and followed the instructional videos on how to service them to the T.

I have no idea what the problem is, and what would cause an inflator to behave like this.

But I'm nervous now because I also serviced the inflator on my doubles wing in the same manner, and next time this happens, I might be beyond a 100 feet or on a deco hang.

I used a generic o-ring kit from Northeastern Scuba Supply to replace the old o-rings. Not sure if that matters.

Any input?

I think I would give to 2 smaller o-rings and their seating surfaces another real close look, focusing on the inner most one. The symptoms you described seen to lead there.

Your shrader valve is bent.

Gene said what I was going to. Replace your schrader valve. I had a situation where I was getting a constant stream of little tiny bubbles on my express tech. Same kind of inflator as the DSS wings. Thought it was the inflator itself. Rebuilt and replaced o rings and just for good measure soaked and cleaned the LP hose. Worked for two dives and started up again. Replaced the schrader and it went away. Valve did not appear to be "bad" but it;s a little tiny thing and I did not feel like getting the magnifying glass out. That was over year and 50 some dives ago. No problems.

Capt.Gene:

Your shrader valve is bent.

Click to expand...

Jim Lapenta:

Gene said what I was going to. Replace your schrader valve. I had a situation where I was getting a constant stream of little tiny bubbles on my express tech. Same kind of inflator as the DSS wings. Thought it was the inflator itself. Rebuilt and replaced o rings and just for good measure soaked and cleaned the LP hose. Worked for two dives and started up again. Replaced the schrader and it went away. Valve did not appear to be "bad" but it;s a little tiny thing and I did not feel like getting the magnifying glass out. That was over year and 50 some dives ago. No problems.

Click to expand...

Guys, the design of the OP's power inflater is different from that of Zeagle power inflaters.
There's a valve inside his power inflater, but it isn't a Schrader valve (like the one you find in bicycle and car tires), per se. Refer to the diagram of the OP's power inflater on the Dive Gear Express website.

When doing the power inflater overhaul for the first time, it's pretty easy to scratch up the o-ring grooves or other critical regions of the metal parts if you don't know what you're doing. Even with a good set of brass o-ring picks, it can be an exercise in patience to remove the small o-rings (-006) on the spool located in the core of the cartridge valve assembly, particularly the one o-ring next to the hex end of the spool. That's a fun one to remove.

Northeast Scuba Supply sells a replacement for the cartridge valve assembly (inflator guts) for $19.
Northeast Scuba Supply sells a brand new power inflater assembly for $25.
I recently purchased a brand new power inflater assembly from Scubatoys for $20.

If the OP is doing deep decompression dives, he's already spending more money on special gas mixes, etc. It makes sense just to replace the entire power inflater assembly. Then he won't have any anxious thoughts about a stuck "ON" power inflater on his next deep dive.

Bubbletrubble:

Guys, the design of the OP's power inflater is different from that of Zeagle power inflaters.
There's a valve inside his power inflater, but it isn't a Schrader valve (like the one you find in bicycle and car tires), per se. Refer to the diagram of the OP's power inflater on the Dive Gear Express website.

When doing the power inflater overhaul for the first time, it's pretty easy to scratch up the o-ring grooves or other critical regions of the metal parts if you don't know what you're doing. Even with a good set of brass o-ring picks, it can be an exercise in patience to remove the small o-rings (-006) on the spool located in the core of the cartridge valve assembly, particularly the one o-ring next to the hex end of the spool. That's a fun one to remove.

Northeast Scuba Supply sells a replacement for the cartridge valve assembly (inflator guts) for $19.
Northeast Scuba Supply sells a brand new power inflater assembly for $25.
I recently purchased a brand new power inflater assembly from Scubatoys for $20.

If the OP is doing deep decompression dives, he's already spending more money on special gas mixes, etc. It makes sense just to replace the entire power inflater assembly. Then he won't have any anxious thoughts about a stuck "ON" power inflater on his next deep dive.

Click to expand...

I know. I'm not speaking for Gene but the schrader I'm talking about is the one in the LP hose itself. There's one in there.

I'm with Bubbletrubble. I service my own inflators, but they have a lifespan, and it is very easy to scratch the soft brass. The replacement cost of the entire assembly is so low that it simply isn't worth taking the risk of an explosive ascent (I know of someone who was badly bent from one). From now on, if a simple service doesn't fix all the problems, I'm just going to replace the unit.

Jim Lapenta:

I know. I'm not speaking for Gene but the schrader I'm talking about is the one in the LP hose itself. There's one in there.

Click to expand...

Oh, you were talking about the Schrader valve inside the end of the inflater hose. AFAIK, inside the Zeagle power inflaters, there is a valve insert assembly that functions a lot like a Schrader valve. I thought that's what you were talking about. Sorry about the misunderstanding.

Hmmm. You described the problem on your Express Tech as a "constant stream of tiny little bubbles" which was fixed by replacement of the Schrader valve. I'm guessing that the bubbles were emanating from the junction of the LP inflater hose and the power inflater and it didn't matter whether you were pressing on the inflater button or not. If that's the case, I'm very surprised that the Schrader valve replacement fixed your problem. I would have just changed the o-ring in the end of the inflater hose. Unfortunately, it's one of the most problematic o-rings to reach.

I like that term. Problematic. I'd have said pain in the ass or a bitch to get to.

I'm wondering if you can replace the inflator with the Zeagle BX, which would make a nice system for flushing out your wing, and only cost $40 or so.

Adam