Scubapro knight hawk - hose dump valve issue

[right_on]

hi scubapro,

last weekend i was at catalina diving. i am using a scuba pro knight hawk bc. i purchase back in july 2012. i have about less than 10 dives with it. the dump valve on the upper left shoulders leaked air on me while i was 30ft down.

dive 1: bc works fine, no problem. at the end of the dive, i added a little air and i heard the purge valve leaked air like my bc was full. i touched the bladder it was empty. so i started my kick up and went up next to the mooring line. as i was on the surface i can't establish my buoyancy. everytime i add air to my bc, it would go straight out on the purge valve/hose dump on the upper left of my shoulder. so i just went and swam to the stairs/shore and stood up. i yank the hose hard and tried it again, this time it inflated. i ignored the issue and went on thinking it was operator error.

dive 2: went fine no problem...

dive 3: the same thing happened, this time i just stayed at the bottom and checked the bc made sure it was not operator error. so while i was under water i examined my bc - checked made sure none of my hoses are entangled with the dump hose and that it wasn't hitting the dump switch. it was clear that the purge was free of my hoses. i added air using the inflator and it came straight out of the dump valve. my dive buddies 2 of them were watching me fix my bc and they were made aware of my problem before dive 2 and 3 started. i told them to keep an eye on me incase it started leaking again. so i made a decision that i can't fix my bc under water and that it was not an operator error. so i swam to the stairs/shore again and exited. from there, i pulled my hose hard and it started working.

i took my bc to pacific wilderness in san pedro ca. since that's where i bought it from and had them take a look at it. none of the techs there can find the problem with the bc. i know it's hard to duplicate because it was intermittent issue. i don't want to have to second guess my equipment when i'm in a dive. is this a known issue? what can you do to help me with this? i want to be able to trust my bc again. i love my scuba pro knight hawk, i just don't like this intermittent issue. especially when they're only a couple of months old and less than 10 dives.

please help! - charlie

 

[Shftrdog]

It sounds to me that there might be something wrong with the rubber gasket or the spring to hold the valve shut. You could chech the rubber gasket and make sure does not have any cracks in it. Also you could take the spring out and change it with one of your other dump springs and see if that works. I would try calling their customer service, and see what they say. Good luck

 

[SCUBAPRO Harry]

Please contact Tech Support to discuss to be sure all is working correctly: 800-382-2211

 

[right_on]

scubapro harry - i talked to jules from scubapro tech support about my bc. i dropped of my bc with pacific wilderness. they are unable to duplicate the issue. jeff from pacific wilderness talked to jules about my bc today. i don't have any update with it yet. i'll call pw later and find out. i hope everything will be ok...

---------- Post Merged at 07:29 PM ---------- Previous Post was at 03:29 PM ----------

so here's where it stands right now. jeff the owner of pacific wilderness and jules the tech at scubapro said it was an operator error or the buddy dump valve switch was hitting either my tank, hoses or both. apparently the dump valve NEVER goes bad. ever since both of them were in business, this is the first time this issue was ever heard of - over 30 years experience.

what i don't understand is, why do i have to pull the hose hard to get it to inflate back. i'm sure between the swim, walking and setting the gear down. it would have cleared the "entanglement" of the hoses. i'm diving the bc on sunday at PW pool to check it out. i'm going to hawaii on wednesday and will be diving there, i'm taking my bc with me. i really hope they are right, that it was just me.

me? i'm not happy with this because i know i tested it myself on my 3rd dive when it didn't inflate again. i had 2 witnesses watching me inflate it.

 

[SCUBAPRO Harry]

How did the pool check out go ?

 

[Jim Lapenta]

Those valves do go bad. Especially on pull dumps. The cable inside can get fouled or crusted up if you haven't rinsed the BC properly. Also pulling too hard, too many times on the dump may weaken it and you'll find the whole hose in your hand at some point. Most likely at depth. Take the thing off the BC and look at it yourself. Or have another tech or more experienced diver that services their own gear look at it. Best thing is to just toss the whole pull dump asembly and put a plain elbow on it. You have other dumps for releasing air. Pull dump on the inflator is another point of possible failure. Eliminate it.

 

[right_on]

Those valves do go bad. Especially on pull dumps. The cable inside can get fouled or crusted up if you haven't rinsed the BC properly. Also pulling too hard, too many times on the dump may weaken it and you'll find the whole hose in your hand at some point. Most likely at depth. Take the thing off the BC and look at it yourself. Or have another tech or more experienced diver that services their own gear look at it. Best thing is to just toss the whole pull dump asembly and put a plain elbow on it. You have other dumps for releasing air. Pull dump on the inflator is another point of possible failure. Eliminate it.

i rinsed my bc and soak it in water and shampoo every after dive. i've only had it for 3 months and probably have 15 dives with it. i want to disable the dump valve, but that's a band aid fix. you should have 100% confidence with your equipment especially when it's brand new. pacific wilderness tech and checked it out and said nothing was wrong. they're scubapro dealer and qualified to service it. but still unable to find the issue.

How did the pool check out go ?

the pool check out did fine as expected. tech at PW thinks it's my hose tangled, or i was over inflating it. if i was over inflating it, i'd be floating as supposed to be under water or unable to get buoyancy once on surface. i took my bc to hawaii with me and did 4 dives. while i was in hawaii last week, the same thing happened on one of my dives. i just kept pulling the shoulder dump valve hose until it allowed me to inflate again after a few tries. so i dunno what and who to deal with this issue. seems like no one else wants to get involved and help fix it. it's so intermittent that it doesn't happen whenever you want... so what else do you suggest should i do? i can't even sell it knowing that there's something wrong with it.
i like the bc, just can't trust it fully until the problem gets fixed.

 

[FrohnaMO]

I had a very similar issue with my knight hawk with air 2! The issue with mine was not that it was leaking air out of the valve but that the valve was not fully closing, i could reach back and flip the instructor valve button and it would click allowing me to inflate the bc as designed. My tech at the dive shop(nick at Y KI_KI) discovered that if he pulled on the air 2 he could duplicate the issue, he removed the hose repositioned the plastic connecting rod moving it to a different hole which seems to have fixed the issue. I hope this will help you with yours!

 

[Gyo]

Is there any updates on your Knighthawk? I just recently bought one and came across to your problem. Hopefully this is not the manufacturers' defect.

 

[right_on]

Is there any updates on your Knighthawk? I just recently bought one and came across to your problem. Hopefully this is not the manufacturers' defect.

no updates really. i sent it for service to scuba pro and they said they can't find anything wrong with it and sent it back. i never took it to open water anymore. i just use it for pool training sessions. i have switch to a different brand bp/w.