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emanchester Samba Member
Joined: December 17, 2004 Posts: 117
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Posted: Tue May 31, 2016 6:04 pm Post subject: Air Line Rupture |
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I'm not sure if this is the most correct forum or not. I have a 61 bug with air-ride, bags in the rear and air shocks up front. I have had the supply line rupture on me, not once but twice now. Does anyone have any idea why this line would just rupture? Luckily both time have been while its parked in the garage and not driving it. It is the same line, in about the same spot that has ruptured. The line is DOT approved air brake line. Its kind of hard to see in the pic but this is right off the nitrogen tank regulator, inside the cab behind the back seat. Nothing rubbing and no heat from anything
I would like any thoughts on what is happening to the line.
This also has me rethinking the idea of air-ride as this could've been catastrophic had it happened at 60 MPH!!! Has anyone added a custom bumpstop that would prevent the front beam from hitting the ground if it suddenly loses pressure like that?
Thanks in advance and feel free to move this to another forum if more appropriate.
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grandpa pete Samba Member
Joined: July 06, 2008 Posts: 6426 Location: St. Petersburg, FL
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MMW Samba Member
Joined: April 30, 2012 Posts: 846 Location: northern NJ
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Posted: Wed Jun 01, 2016 4:28 am Post subject: Re: Air Line Rupture |
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I have no answer for you but this is one of the problems with a 100% air system with no safety built in. If you look at any factory air system it will not collapse to the point of laying frame or jamming the tires into the fender wells both of which could be catastrophic at highway speeds. Of course you can't get the "look" & have it safe during a failure.
That being said many people run air suspension without ever having an issue.
Since it ruptured in the same spot twice there must be something contacting it or to tight of a bend, etc. _________________ Mic
1959 356 coupe
Missing the original engine 72488
Update - third pc. found!
Now just need the case halves.
1965 fenderless beetle |
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Drewmon Samba Member
Joined: February 22, 2016 Posts: 226 Location: Maine
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Posted: Wed Jun 01, 2016 6:19 am Post subject: Re: Air Line Rupture |
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Was it the same brand of hose that blew both times? Maybe find a stronger line to use? |
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emanchester Samba Member
Joined: December 17, 2004 Posts: 117
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Posted: Wed Jun 01, 2016 6:57 am Post subject: Re: Air Line Rupture |
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Grandpa: the hose is about 3 years old now. First time it ruptured it was only 6 months old maybe. I thought maybe it was nicked when i installed it or something.
MMW: The secondary safety system is what I think I should install. Maybe a bumpstop that will keep the beam 1" off the ground. That way I wouldn't lose total control if the line ruptures again. I'm also going to install a check valve behind each fill valve to keep the pressure in the shocks/bags if this happens again. There is nothing that can contact the hose within 6" of where it ruptured. It almost looks like the line got hot and bubbled first then ruptured.
Drewmon: It is the same type of line used both times.
I just realized the line is only rated for 150psi working pressure but over 1000 psi burst pressure. I have my nitrogen regulator set to 180 psi (that's what is required to lift with a link pin beam). Could this small about over the rating actually cause the rupture? |
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bluebus86 Banned
Joined: September 02, 2010 Posts: 11075
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Posted: Wed Jun 01, 2016 8:13 am Post subject: Re: Air Line Rupture |
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emanchester wrote: |
Grandpa: the hose is about 3 years old now. First time it ruptured it was only 6 months old maybe. I thought maybe it was nicked when i installed it or something.
MMW: The secondary safety system is what I think I should install. Maybe a bumpstop that will keep the beam 1" off the ground. That way I wouldn't lose total control if the line ruptures again. I'm also going to install a check valve behind each fill valve to keep the pressure in the shocks/bags if this happens again. There is nothing that can contact the hose within 6" of where it ruptured. It almost looks like the line got hot and bubbled first then ruptured.
Drewmon: It is the same type of line used both times.
I just realized the line is only rated for 150psi working pressure but over 1000 psi burst pressure. I have my nitrogen regulator set to 180 psi (that's what is required to lift with a link pin beam). Could this small about over the rating actually cause the rupture? |
your working pressure is 20% over the limit, that might have a bit to do with the rupture problem. use the correct rated hoses and fittings. and yes make some stops so this bug does not slam to the ground at freeway speeds, you could spin out, get killed, kill others, small children etc....
ps i do not see any sign of it getting hot and bubbling _________________ Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
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TinCanFab Samba Member
Joined: April 04, 2006 Posts: 2743 Location: Waterford, California
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Cali_Army_Guy Samba Member
Joined: March 19, 2015 Posts: 2094 Location: Stockton, CA
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Posted: Wed Jun 01, 2016 9:54 am Post subject: Re: Air Line Rupture |
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Where are you located at OP? Is that 3/8" line? _________________ 2015 VW Passat Wolfsburg Edition
1966 VW Beetle - Sold |
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emanchester Samba Member
Joined: December 17, 2004 Posts: 117
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Posted: Wed Jun 01, 2016 10:12 am Post subject: Re: Air Line Rupture |
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The current plan is to take it off the road until I get some sort of stop figured out. Just not worth the risk to me or anyone else. I may even go back to torsions in the front.
I'm in Colorado, about an hour north of Denver. Yes it is 3/8" line.
Thank you all for the input. I'm hoping to get this figured out soon. |
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emanchester Samba Member
Joined: December 17, 2004 Posts: 117
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Posted: Wed Jun 08, 2016 1:09 pm Post subject: Re: Air Line Rupture |
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I finally had a chance to look at the air line a little closer. What happened was the outside part of the air line is all that ruptured, the black part. If you look at the pic you can see the whitish inside part is sill intact with the reinforcement thread still wrapped around it. I cut out the damaged area and was going to hook it back up to inflate the suspension so I can move it into position in my garage to take the front beam off and I noticed the part I cut the line is also separated. It looks like a stray thread was in between the two layers during manufacturing and didn't allow the two pieces to glue together correctly. I will now be removing all the line connections to look for this separation anywhere else as well.
Mystery solved! Now onto the task of fabricating some sort of bump stop up front. Any ideas for that?
Thanks
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raul arrese Samba Member
Joined: July 23, 2006 Posts: 1329 Location: miami florida
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Posted: Wed Jun 08, 2016 6:03 pm Post subject: Re: Air Line Rupture |
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That hose is garbage , I don't run that on anything I build , I only use aircraft stainless , Teflon ptfe hose on everything I do , fuel , air , oil, everything ... and pressure in the thousands... do it right and forget it ... _________________ " Hot vw feature , may 2014 issue "
" 2013 Bug Jam class winner "
" Bug Jam best motor and best paint "
" 2013 Lakeland Classic Best of Show "
" 2014 Show and Shine , First in class "
"
Like my facebook https://www.facebook.com/pages/Raul-Arrese-custom-fabrication-and-performance/1832968110262608 |
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rsthj Samba Member
Joined: December 16, 2015 Posts: 65
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Posted: Wed Jun 08, 2016 7:02 pm Post subject: Re: Air Line Rupture |
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Problem is unlikely to be the line and more likely to be an incompatible combination of line and fitting. If the fitting is the type that it appears to be (push-to-connect) it will alway expose the outer covering to pressure and eventually rupture. That outer cover is for abrasion resistance, UV protection and the like. But not pressure. Assuming this is the case, change your fitting to match your line or line to match your fitting. |
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emanchester Samba Member
Joined: December 17, 2004 Posts: 117
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Posted: Wed Jun 08, 2016 8:38 pm Post subject: Re: Air Line Rupture |
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rsthj - would non-reinforced tubing be better? I can't find anything that's states type b, reinforced, tube can not be used with push to connect fittings. But it makes sense that the outer covering would be exposed to some pressure from the fitting.
Maybe I should switch out the tubing for type a, non-reinforced ? |
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rsthj Samba Member
Joined: December 16, 2015 Posts: 65
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Posted: Wed Jun 08, 2016 9:39 pm Post subject: Re: Air Line Rupture |
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emanchester wrote: |
rsthj - would non-reinforced tubing be better? I can't find anything that's states type b, reinforced, tube can not be used with push to connect fittings. But it makes sense that the outer covering would be exposed to some pressure from the fitting.
Maybe I should switch out the tubing for type a, non-reinforced ? |
Best bet would be to talk to a shop that does air brakes. They will be able to sell you a known good tubing/fitting combination.
FWIW, I only non-reinforced tubing with push-to-lock fittings but the application has been very different (not automotive). When I need reinforced tubing, I'll use a fitting that seals to the inside of the tubing. |
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noahtibbetts Samba Member
Joined: February 18, 2007 Posts: 11 Location: oceanside, ca
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Posted: Tue Jun 28, 2016 10:58 am Post subject: Re: Air Line Rupture |
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I'm wanting to put air ride on my '64. Are there any other options besides AirKewld's? I've researched their prices and they only proprietary thing they have are their weld in brackets to mount the air system. |
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raul arrese Samba Member
Joined: July 23, 2006 Posts: 1329 Location: miami florida
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Posted: Tue Jun 28, 2016 11:02 am Post subject: Re: Air Line Rupture |
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noahtibbetts wrote: |
I'm wanting to put air ride on my '64. Are there any other options besides AirKewld's? I've researched their prices and they only proprietary thing they have are their weld in brackets to mount the air system. |
If you have the capability than you can make and buy all you need to get it done ... thats what i do and most guys out there ... they use a common available rear bag and monroe air shocks up front , and thats just one way to do it , few other route's you can take like single bag up front or even hydraulic integrated into the torsions... _________________ " Hot vw feature , may 2014 issue "
" 2013 Bug Jam class winner "
" Bug Jam best motor and best paint "
" 2013 Lakeland Classic Best of Show "
" 2014 Show and Shine , First in class "
"
Like my facebook https://www.facebook.com/pages/Raul-Arrese-custom-fabrication-and-performance/1832968110262608 |
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Cali_Army_Guy Samba Member
Joined: March 19, 2015 Posts: 2094 Location: Stockton, CA
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Posted: Tue Jun 28, 2016 1:26 pm Post subject: Re: Air Line Rupture |
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noahtibbetts wrote: |
I'm wanting to put air ride on my '64. Are there any other options besides AirKewld's? I've researched their prices and they only proprietary thing they have are their weld in brackets to mount the air system. |
Jer-Fab does air ride. $2100 for a full bolt on kit. No welding, no removal of body. _________________ 2015 VW Passat Wolfsburg Edition
1966 VW Beetle - Sold |
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