Mountain Buzz banner

Vanguard A6 valve question

4K views 21 replies 8 participants last post by  Plecoptera 
#1 ·
I have a used Vanguard 14' SB, and noticed the floor seems a bit softer than some other manufacturer's boats. I have checked every inch of the floor, and no, I don't have any leaks. What I did find is I have a blue dot Leafield A6 value, which should be a 2# valve. Holly rates her floor to 2.9#, so the valve could be the problem. But, I have also spoken to some other people, and their reaction is "it's an I-beam floor, they don't take pressure well".

I got the boat used from a outfitter, who uses Vgards as mostly a paddle boat on Shoshone, and who may/may not have replaced the valve. Holly is reportedly in Europe, Clavey isn't sure, no one at the outfitter remembers replacing the valve on a boat they sold five years ago.

So, do any Vgard 1402 owners know what A6 valve their boats have, and is it stock, or did you replace it?
 
#2 ·
Is the PRV releasing before the floor is stiff? It could have some grit in it that is letting it release a little earlier than it would if it was clean. Those things are so finicky, always on the verge of leaking . Clean it up and see if that helps.

Not sure if the VG comes with a blue dot or not but I all but guarantee that the PRV has been changed over the years at the outfitters. It is the number one cause of floor leaks in the shop. If she rates her floors to 2.9 you could bump up to brown for sure (2.25), probably even white (2.5). Most VG floors I have dealt with are pretty damn stiff so I'd say make sure it is clean and if it is, bump up.

(disclaimer: if you rely on a prv of any dot color to release and not blow I beams Raftfix has no responsibility).
 
#3 ·
My 14' Vanguard has Leafield C7 valves on all chambers including the floor. I can pump the floor stiff enough that there is hardly any flex at all. Way stiffer than my NRS. The only time the PRV valve has gone off is when the boat is fully loaded for a muti day, then I just bled off a little air.
 
#4 ·
The floor should be pretty hard but just like Z said, PRV’s are notorious for having issues. Holly sent me a new one at one point and just said they go bad all the time. Could have some grit, but also shoot a spray or two of 303 in there to condition the rubber. I usually do that all round too.

Honestly, I’m not sure the prv’s aren’t more trouble than they are worth. You can buy a rubber plug made to fit the top, I generally use that. I don’t think it makes it airtight but seems to help a bit keeping the pressure up.
 
#7 ·
My 5 year old 1402 Vanguard came equipped stock with a Leafield A6 Blue Dot PRV. I replaced it with a new A6 blue, and it pretty much started leaking right away. Somehow in my ignorance (since I didn't realize until now that there were different rated prv's), I ordered the "correct" replacement PRV and didn't get a 6 lb valve and trash my floor. That being said, the floor is always too soft, so a brown dot prv sounds interesting.
 

Attachments

#11 ·
It's not much more than a mark from a colored magic marker on the pop top looking down, but there is enough left to know my current one is a blue. Google Leafield, and you will discover there is a wide range, and yes, brown is 2.5#.

I could see where a shop where the boats were taking a lot of hits might want a lower pressure. I have been running low enough that I wasn't getting any release, and may just crank it up to the full 2# and try and see. I don't think it's leaking from grit. I have been a wienie in general on pressure, and only started to crank the side tubes up to a full 2.9#. The boat handles much better when it's hard.

I've emailed Holly, I will post here if/when she responds.

Thanks all.
 
#10 ·
I've got a 14ft VG too. I've had to replace the PRV a few times and it always fixes a soft floor. That being said, getting it to be firm hasn't been an issue. Until know I didn't realize there were different types of PRV's...
Time to go look for a small dot.
Love the Buzz... Always learning stuff here.
 
#12 ·
The dots are frequently scrubbed off by silt and water. In the last few years Leafield figured it out and started stamping the pressure in the body of the valve instead of just the dot. Older valves without the stamp and dot are anybodys guess. I once thought I could measure the spring. Then I opened a bunch of valves of the same pressure to find different lengths. So much for that.

When I pull them apart I can tell if its a yellow by compressing the spring. I can tell its not a blue or yellow if its white stiff. Telling a blue from a brown or a brown from a white takes more touch than I have.
 
#13 ·
Interesting. I am a noob at dotted A6s. Passed thru the NRS site, one highly liked review said it was time for a better design for the valve. Seems like a good idea. Why did anyone think a recessed top that gets submerged was a good idea... I pulled mine to examine it, at least the inside of my floor is dry.
 
#15 ·
Mine is probably 10 years old, I don't ever remember seeing a dot either. Probably long gone, might be time to look at a new one.

Pump that boat up nice and firm, it can take it and you'll like it better. I always just pump the floor until the prv goes off.
 
#16 ·
I always just pump the floor until the prv goes off.
You can get away with it but I dont recommend this approach for a couple reasons. Often times a PRV will start to leak after it blows once. It doesnt always reseat itself perfectly, if it doesn't, it will leak. If there is silt present and the valve plunger reseats on top of the silt it will leak. The leak isn't always real noticable, just top off in the morning noticeable. On my 12' NRS I can go for a week without topping off my floor, if I have to top it off, I check the PRV. Its always been the culprit.
 
#17 ·
Heard from Holly, she says stay with the blue 2# and replace the valve.

what you are describing pretty closely matches what I am experiencing. I overpumped on a Deso trip last fall, just a bit with a K100, but it vented and since has gotten progressively worse. I top off in the morning and get by.
 
#19 ·
Glad you heard from Holly. It's always best to go to the source. I think I'll get an extra valve in my repair kit. I have experienced the same problem of the valve popping off when the floor doesn't seem to be very hard. I took it apart and cleaned it but I'm not really sure I've solved the problem. I guess a pressure gauge would be a handy piece of equipment too.

PVC boats can't handle the pressure that Hypalon can so I work about over pressurizing the tubes also. This is especially critical when I leave the boat on the beach in the sun after boating.
 
#20 ·
I do what opsrey does (pump unitl it blows off) in the two rafts I have with ibeams (Hyside, NRS) . In fact I let it blow off once on land, put the boat in water to cool down, load up and then pump until blow-off again. I had issues with grit getting into them until I put those screens in the valve. Haven't had an issue since, literally years. Heck, my Hyside's floor is 24 years old...the nrs is 4....and having a really stiff floor is a big deal to me.

I do carry a plug just in case, but 90% of the PRV issues I have personally seen (and I've surely seen way fewer than zbaird) are resolved by cleaning out the valve.
 
#22 ·
Okay, thru a not terribly generous contribution from Colorado PERA, A6 valve research continues...

I've pulled mine, and even though I always have had the filter screen over it, it has still accumulated an interesting amount of very fine grained particulate. Examination has not been able to establish whether it managed to get between the plunger and the gasket, but it also cannot be excluded.

The particulate matter has hardened to a resistant mass. Submergence for an interval of less than 5 minutes in a solution of hot water and Dr. Bonner's soap loosend some, but not all, of the mass, and exposure to a flow of hot tap water succeeded in flushing it thru the valve. A residual amount of the mass has remained, and is being exposed to longer duration submergence.

The actual mechanics of the valve has been examined, and it seems to have [at least] two potential problems:

First is actual leakage caused by the plunger being elevated above the diaphram by the accumulated particulate.

Second is a weakening of the resistance to air pressure causing the valve to release early.

Paradoxically, the leakage problem caused by the particulate accumulation could work to counter the problem of early release, although either could contribute to the problem of a floppy floor. Data collection practices in early phases of this research failed to distinquish between the different problems, so primary cause cannot be established.

It is noted that during field research there was no presence of sustained bubbling or of a hissing sound.

There is a possible connection between the two identified problems areas. It is possible that some form of weak material bond exists between the plunger and diaphram. The bond could be intentionally introduced by addition of a bonding agent such as a glue, or be surface adhesion from two initially clean materials during the manufacturing process. A pressure triggered release of the plunger would break the bond from either source, and the introduction of particulates could further weaken the bond. How this would contribute to early release is not clear, although it could in theory make it harder for delayed release past 2# pressure to occur (assuming the secondary particulate bond was weaker than the primary created during construction).

Possible directions in future research may consist of more experimentation with the addition of a new, unused valve as an experimental control, or just washing the existing valve with 303 and seeing if it fixes it.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top