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Leaking Boston Valve

Posted: Sat Jan 20, 2018 3:55 am
by juandesooka
I have a leaky bladder. I am pretty sure it is leaking from the threads of the Boston valve (the large inflate/deflate style). I cleaned the threads and all the seals, but doesn't fix it. I took out the bladder to confirm it isn't leaking from the connection to the bladder.

Seems pretty weird ... easy to see why the valve connection to bladder fails, with glue delaminating. Have fixed a bunch of these lately. Can't see how the thread mechanism is failing, maybe warped or threads broken or something.

Anyone have any tips on a fix for this, other than replacing the valve or the bladder?

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 4:51 am
by GregK
John - the threads aren't the sealing interface, they provide the clamping force to compress the sealing V-bump on the outer face of the valve body into the rubber washer inside the plug, closing off the 2-way flow path through the valve. Same situation on the cap that covers the 1-way flow portion through the plug, there should be a rubber washer inside the cap that seals against the top edge of the hole in the plug.

Two causes of a leak at the valve body V-bump - plug washer interface that I have encountered :

1. Sand either on the outer sealing surface of the washer or trapped between the washer and its groove in the plug

2. A dimple or compression of the V-bump from a bigger / hard piece of rock/sand closed up in the valve-plug. It is possible to restore almost all of the compression dimple, at least I've had success all three times thus far that I have encountered this cause of a leak.

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 5:15 am
by plummet
Usually when my valves leak there's sand under the rubber seal. Take the seal out and clean. Also spray detergent/water combo over the valve to determine where the leak is coming from. Look for the bubbles

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 7:34 pm
by Peter_Frank
Do you HAVE a rubber seal ?

Asking, as I had one funny situation last weekend out with my 8 m2 kite.

I could hear it slightly "hissing" from the valve after it was pumped hard :(
(I always put the valve up to my ear before and after tightening the valve - this way I am 100 % it goes to non leaking)

Usually a leaking valve when rigging only happens if I get the line to the valve/cap stuck under the seal, so you just loosen and remove and close it again and now its tight :D

But this very kite did not have a rubber seal at all !

I have been riding around 1½ year with this kite, almost 100 sessions, maybe my most used size (out of 8 sizes), it has NEVER gotten flat or soft, just with the plastic ring on the boston valve closing fully tight towards the plastic on the LE side :rollgrin:

Of course, at first when I used the brand new kite for the first time, I thought: The seal must be missing, or what ? Maybe some new material so you dont need the rubber seal nomore ?
As, when just screwed fine and tight, it was NEVER leaking for these close to 2 years :naughty:

Till last weekend...

So I took a new rubber seal ring from one of the repair kits that comes with the kites, and voila - now it is healed and could ride the whole day not leaking now.

Apparently the plastic ring itself had such a perfect fit when new, that it was tight - till last weekend where wear and sand and me getting the line stuck under it, ha haaa.

All my other kites have the rubber sealing, so just curious IF you have this, or just by accident without knowing have had it without this sealing ?
As it seems to work fine for a while when brand new :D

8) PF

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 7:40 pm
by juandesooka
Peter_Frank wrote:
Sat Jan 20, 2018 7:34 pm
Do you HAVE a rubber seal ?
...
All my other kites have the rubber sealing, so just curious IF you have this, or just by accident without knowing have had it without this sealing ?
As it seems to work fine for a while when brand new :D

8) PF
Thanks for the replies guys. Plummet: cleaned under the inflate washer. Was some gunk under there. But that wasn't the problem.

Peter: what you describe seems very similar to what I have going on. Comparing to my other kite with same valve, it appears I am missing the rubber washer that seals the inflate nozzle into the valve! I wonder if it was somehow sealing without this before, as you describe, or if it just fell off. In any case, off to the hardware store, hopefully get lucky and they have something close. If not, the search will be on to find a replacement ... or an aquaseal temporary fix if we get some 25kt-ish wind and I need an 8m. :-)

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 8:33 pm
by Peter_Frank
Great to hear - and you could also, if you get screaming good conditions NOW, take a sealing ring from one of the other kites, till you get a new one :naughty:

8) Peter

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 10:52 pm
by badgb21
Have had the same issue.
Friction with rubber seal kicks in before it becomes air tight.
A bit of spit on both sides of the washer will usually does it, a longer term solution is something like a dab of molycote on both sides of the washer, careful though this will attract sand.

Re: Leaking Boston Valve

Posted: Sat Jan 20, 2018 11:59 pm
by Peter_Frank
badgb21 wrote:
Sat Jan 20, 2018 10:52 pm
Have had the same issue.
Friction with rubber seal kicks in before it becomes air tight.
A bit of spit on both sides of the washer will usually does it, a longer term solution is something like a dab of molycote on both sides of the washer, careful though this will attract sand.

You mean, the same symptoms :rollgrin:

As Juan and I did not have the rubber sealing, and this was the very reason, although impressive it could work for so long without :D

But apparently one can also have "worn" or "polluted" sealing rings, like in your case ?

I really love these "Boston Valves" - easy and fast and one can get spare valves everywhere (but havent had the need to, so they might last almost forever ?)

8) Peter

Re: Leaking Boston Valve

Posted: Sun Jan 21, 2018 7:59 am
by magnusod
GregK wrote:
Sat Jan 20, 2018 4:51 am
John - the threads aren't the sealing interface, they provide the clamping force to compress the sealing V-bump on the outer face of the valve body into the rubber washer inside the plug, closing off the 2-way flow path through the valve. Same situation on the cap that covers the 1-way flow portion through the plug, there should be a rubber washer inside the cap that seals against the top edge of the hole in the plug.

Two causes of a leak at the valve body V-bump - plug washer interface that I have encountered :

1. Sand either on the outer sealing surface of the washer or trapped between the washer and its groove in the plug

2. A dimple or compression of the V-bump from a bigger / hard piece of rock/sand closed up in the valve-plug. It is possible to restore almost all of the compression dimple, at least I've had success all three times thus far that I have encountered this cause of a leak.
Greg,

How did you restore the dimples on the v-bump? Mine has a pretty severe dent on the v-bump which is supposed to seal against the rubber washer. I tried putting an o-ring to seal inside the v-bump but could not get it properly sealed. I believe I got the dent when I packed boards on top of my kites and maybe an edge on the threaded plug got squeezed against the v-bump.

Re: Leaking Boston Valve

Posted: Sun Jan 21, 2018 10:35 am
by badgb21
I was responding to the original poster. I read it before his declaration of no actual washer in place!
I didn’t read your posts cos your emojis do my head in!


I had problem on brand new kite FYI.
Peter_Frank wrote:
Sat Jan 20, 2018 11:59 pm
badgb21 wrote:
Sat Jan 20, 2018 10:52 pm
Have had the same issue.
Friction with rubber seal kicks in before it becomes air tight.
A bit of spit on both sides of the washer will usually does it, a longer term solution is something like a dab of molycote on both sides of the washer, careful though this will attract sand.

You mean, the same symptoms :rollgrin:

As Juan and I did not have the rubber sealing, and this was the very reason, although impressive it could work for so long without :D

But apparently one can also have "worn" or "polluted" sealing rings, like in your case ?

I really love these "Boston Valves" - easy and fast and one can get spare valves everywhere (but havent had the need to, so they might last almost forever ?)

8) Peter