Replacing HP Hose O-Ring Lubricant

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

roninmbattousai

Registered
Messages
13
Reaction score
3
Location
Jacksonville FL
# of dives
0 - 24
Question, I have a HP hose that I believe the O-Ring has failed on (starting to have small bubbles out of the hose near the first stage), while i have the hose disconnected from the first stage should i go ahead and apply a small amount of lubricant onto it before reassembling? I dive nitrox with this so I also am wondering if I should be adding specifically Christolube to it due to O2 interaction and such.
 
replace the oring right away. i am sure some reg techs will give solid advise on this. my opinion is that no lube is required and may actually be counter productive.
 
  • Like
Reactions: Zef
Lube just enough to make it shiny, it helps the oring slide against the first stage, don’t over tighten it. In this case I would probably use an O2 compatible grease but silicone should also be ok in this situation but why chance it, if you have the right stuff.
 
The o-rings on the hose fittings are only dynamic o-rings as the hoses are tightened, once the hoses are attached, the o-rings are static and do not rely on being lubricated to form a seal. There is nothing wrong with living these o-rings but the amount you should use is miniscule. If you are only using nitrox mixes up to 40% then you should be ok with silicone grease but an O2 compatible grease would work as well but be much more expensive for the teany tiny amount of grease one would use in this application.

I recommend just replacing the o-ring and be done with it. Take some heat shrink or painter's tape and use it to cover the hose fitting threads to protect the o-ring as you install it on the end of the hose, then remove the protector and attach your hose to your 1st stage slightly more than hand tight.

If your 1st stage is still leaking the it requires further service. Reinstalling a leaking fitting after lubing the old o-ring instead of replacing it, is akin to putting lipstick on a pig.

-Z
 
@herman always yells at me because this o-ring is dynamic when it is installed but static afterwards, but I do not typically lubricate this o-ring upon install. If you are diving with standard nitrox it doesn't need to be christolube, but I do personally use it on all HP side applications since I use O2 quite a bit.
 
Thanks guys, yeah the intent is to replace before the next dive. Christolube is somewhat difficult to get locally it seems just since the local shops just buy in some large bulk instead for o2 lube, but i'll see if I can ask some other shops nearby. I dont mind paying the additional cost for safety and i've got a second setup as well that i maintain (not sure on shelf life either for the product). Good to know about the trick with tape for protecting the threads instead of having the special tool or anything for it (only watched Alec Pierce's video about replacement for this oring before debating purchasing the lube).
 
Question, I have a HP hose that I believe the O-Ring has failed on (starting to have small bubbles out of the hose near the first stage), while i have the hose disconnected from the first stage should i go ahead and apply a small amount of lubricant onto it before reassembling? I dive nitrox with this so I also am wondering if I should be adding specifically Christolube to it due to O2 interaction and such.
Everyone here has assumed this is an O-ring problem. But as I read it, the bubbles are coming from the hose, and not the fitting. If so, then this HP hose has to be replaced, immediately. The Suunto Cobra had such a problem, and there was a recall on the hose. So if the bubbles are coming from the hose, the hose may be subject to rupture.

SeaRat
 
Pressurize the rig, place it under water and look carefully. If you cannot tell where the bubbles are coming from, replace the o-ring (they are very cheap) and try again. HP hose bubbles look like those from an aquarium air stone.
 
https://www.shearwater.com/products/swift/

Back
Top Bottom