Slow leak from seam rupture? - Mountain Buzz

Thread Tools Display Modes
Old 08-30-2017   #1
Join Date: Mar 2004
Posts: 85
Slow leak from seam rupture?

Hey, so I've got a raft leak that has me stumped. Can't locate it anywhere with soapy water and am getting tired of looking for it. So a couple questions if anyone can help:
First, if the leak was caused by failure to bleed the tube enough for the hot weather (a definite possibility), would it be more obvious? Is it possible for that to occur at the seam but still hold air for a couple days, or is that more likely to be a major rupture?
I haven't messed with the valve yet, but I did try to soap it up and saw what I thought was a very large bubble (the width of the entire valve) form and pop pretty quickly. Difficult to replicate that result so I wasn't sure what to make of it. Is it more difficult to find a slow leak at the valve with soap bubbles? Can expansion due to heat affect a valve too?
Is there anywhere else I should be focusing my attention? Boat is a PVC Vanguard.
Thanks for any insight here. I'd really like to get this sorted out and fixes before the season ends.

willoughby is offline   Reply With Quote
Sponsored Links
Old 08-31-2017   #2
Osprey's Avatar
Join Date: May 2006
Posts: 774
Sounds like the valve. When was the last time you 303'd them? Seems like the rubber seal hardens over time, every couple years I have spray a bit of 303 into the valve and the slow leak stops. I have a vanguard too.

If it was failure due to expansion it'd be obvious. They can hold a ton of pressure though.

Or if you are super perplexed take it into inflatable tech and let them take a look. If you did have a warranty issue he can call Holly and fix it right up.
Osprey is offline   Reply With Quote
Old 08-31-2017   #3
Join Date: Mar 2004
Posts: 85
Thanks for the useful feedback, Osprey. I'll pull the valve apart and take a closer look today.
willoughby is offline   Reply With Quote
Sponsored Links
Old 08-31-2017   #4
Osprey's Avatar
Join Date: May 2006
Posts: 774
Iím not sure you could see anything, just make sure the collar is tight and I just spray it right into the valve. Just make sure you donít have a bunch of pressure in the tube. Or the next time you push the plunger/spring down you might get a face-full of 303 lol (ask me how I know). Unless the valve is dirty, if you have some sand or something in there that could give you a slow leak. If you take the valve out donít drop the backside down in there and have to fish it out, best to do flat.

Since you said you already sprayed the boat down and nothing showed up, I canít think of anything else it could be. From your description we arenít talking about the floor right? Those PRVís are going to leak no matter what you do.
Osprey is offline   Reply With Quote
Old 09-01-2017   #5
Join Date: Oct 2005
Posts: 15
I assume you have the C-7 valve and is leaking through the core. Break valve loose with chamber inflated tight. Finish removing with chamber deflated. Pull plunger off valve remove spring and stretch slightly-just a little. Reassemble with 303 protectant on plunger and inside and outside valve hole. Reinstall medium tight, reinflate and finish tightening valve a quarter turn or so. By the way-valve cap is designed to hold air if o-ring is still present.
The hardest leaks to find are medium ones. Large are obvious cause you can put your hand inside chamber, small ones make nice soap bubbles(a few drops of glycerin hrelps), but the medium ones blow out air fast enough so that bubbles are unable to form. The ear works better than the eye here. Plunge towel into bucket of soapy water, sheet water over sections of the raft and listen. You'll only get a second or so to hear it.
"Is it possible for that to occur at the seam but still hold air for a couple days"---Absolutely-any size is possible. Compromised baffles make leak finding even more of a challange because chambers are sharing the same air. Doc
bodfishblues is offline   Reply With Quote
Old 09-02-2017   #6
ColoradoDave's Avatar
Western Slope, CO, Colorado
Paddling Since: 2009
Join Date: Jun 2010
Posts: 290
I've seen slow leaks in a valve that didn't blow bubbles for a while. I filled the outside part of the valve with soapy water and in the morning it was a mass of tiny bubbles about 4 inches in diameter.
ColoradoDave is offline   Reply With Quote
Old 09-03-2017   #7
Wondervu, CO, Colorado
Paddling Since: 2001
Join Date: May 2008
Posts: 492
NRS sells a C-7 valve repair kit for about $10. Includes new spring, plunger and rubber seal. Their web site even has a 'how to' video. Go to the following link..

and search for...

Leafield C7 Repair Kit Parts
kengore is offline   Reply With Quote
Old 09-03-2017   #8
Join Date: Oct 2005
Posts: 15
Although I've replaced maybe 5 valve kits for the B7 over the years(all due to cracked or otherwise degraded plungers)none so far in the C7's. Slightly stretching the spring along with some 303 has always worked. Plain water-no soap works better on checking valve cores(use soap on the perimeter).
One more note on valves: I find that whether it's a commercial or private boat that the owner deals with the problem of a p/r valve letting out too much air, but few check to see that valve is releasing after pressure goes above safe zone and next to baffles, blown I beams can be the most expensive repair for SB rafts.
bodfishblues is offline   Reply With Quote
Old 09-04-2017   #9
BoscoBoater's Avatar
Join Date: Jul 2006
Posts: 245
Have you tried just tightening the valve? I usually have to tighten mine once a year or so.

I like to try the free and easy stuff first.
BoscoBoater is offline   Reply With Quote
Old 09-06-2017   #10
Join Date: Mar 2004
Posts: 85
I did some valve cleaning, tightening and 303ing over the weekend and it seems to be working. Hot days and cold mtn nights translate to big pressure swings in the tubes but the problem area seems to be about the same as all the other tubes now. Hasn't gone flat again yet, anyway. Thanks for everyone's input!
willoughby is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Topic Thread Starter Forum Replies Last Post
SLOW MountainBuzz Homepage The Mogur Support & Feedback 16 03-18-2013 06:11 PM
Slow melt yak1 Whitewater Kayaking 4 05-23-2011 10:25 AM
seam tape MarkB2 Kayaking | Gear Talk 2 07-22-2010 12:55 PM
Super slow buzz?? tellutwurp Whitewater Kayaking 29 04-25-2007 10:22 PM
egads! it's slow as snot mvhyde Support & Feedback 6 03-15-2007 08:57 AM

» Classified Ads
Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 11:58 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.