Seems like most I've run across have used 1/4" fittings instead of 3/8". Is it just availability or some other reason?

Everything on mine is 3/8" all the way to the tank and even the hose to attach to the tank. The only 1/4" fittings are to the gauge under the hood, the pressure switch and the gauge on the tank itself. It only drops to 1/4" at the outlet of the working hose.

My hole system is going to be 3/8 NPT and 1/2" hose. I haven't got it together yet but I have most of the parts:rolleyes:

1/4" is just alot more common. I went with 3/8 fittings throughout the entire system cause I didn't want to restrict the airflow in any way.

When I was setting up my system a couple of engineering types told me that 1/4" is more than sufficient for the volume, pressure and flow rates we're dealing with on a OBA system. Works for me.

Paul

Originally posted by nasvik
When I was setting up my system a couple of engineering types told me that 1/4" is more than sufficient for the volume, pressure and flow rates we're dealing with on a OBA system. Works for me.

Paul

It all depends on what the OBA is going to be running. If you're just using it to air up tires, then it comes down to a matter of "how expensive if your time" as in "larger fittings flow more air resulting in faster ....... " you know the rest.

If you're going to be using it to run impact tools or to reseat beads, then your best bet is to go larger than 1/4". 3/8 is good. 1/2" is better.

And those spiral wound 1/4" hoses ... forget 'em if you're looking for flow.

cm "just another engineer's opinion" k

Becuase a york does not put out anywhere near enough air for any bigger than 1/4" fittings, and 1/4" is cheaper ;)

Phil

cmk - what air system are you running? :D

Paul

Air tools run just fine on 1/4" fittings and 3/8" hose.

York does not put out enough air to keep up to the "low flow" 1/4" stuff anyway.

Here's an example. Undo one of your 1/4" fittings so it is open, and fire up the Jeep. Can you build pressure against that "restrictive" 1/4" fitting? Hell no :flipoff2:

Phil

Originally posted by nasvik
cmk - what air system are you running? :D

Paul

I hear ya' man.

I do like to think that the 6 figure industrial systems I've designed do afford some credentials on my part ... on top of the numerous OBA systems I've watched buddies hodge podge together literally blow up in their faces.

As I said ... it's all in what you plan on doing with an OBA system and what you expect out of it. If you expect to be able to seat beads with it, don't expect to do it with 1/4" fittings, quick disconnects, and yards of small diameter tubing.

cm "got a york ... just not the right one" k

That's what I thought. :flipoff2:

I've run the same York for 4 years now. Anyone that's wheeled with me knows I spend a lot of time with air tools, reseating beads and I air up my 38" tires *at least* two at a time. Lots of quick connects, manifolds and all in 1/4" fittings.

1/4" is fine for our application, and I can't imagine 3/8" could make my system any more efficient.

Paul

Originally posted by cmk


It all depends on what the OBA is going to be running. If you're just using it to air up tires, then it comes down to a matter of "how expensive if your time" as in "larger fittings flow more air resulting in faster ....... " you know the rest.

If you're going to be using it to run impact tools or to reseat beads, then your best bet is to go larger than 1/4". 3/8 is good. 1/2" is better.

And those spiral wound 1/4" hoses ... forget 'em if you're looking for flow.

cm "just another engineer's opinion" k

Do you have stats on PSI drops through a 1/4 fitting, and or lengths of hose/pipe?

I have a ton of data on liquids, but not air...

Originally posted by nasvik
1/4" is fine for our application, and I can't imagine 3/8" could make my system any more efficient.

Paul

I agree.

Especially when airing up tires- the tire valve is going to be the biggest restriction by far.

Does anyone know if there is a 3/8" coiled work hose out there. Cant find one. Mine is 3/8" and 1/4" at pressure switch and such as mentioned, 3/8" hose. but I hate having to drop to 1/4" coil for air tools and stuff. Like to find some 3/8" or I may start carrying 20' of rubber line. and use it when I need that extra umpff. Works great as is though.

Paul,

I'll be honest with ya' man, you're the first guy I've heard from that has successfully reseated beads with a 1/4" system. I've watched guys try to do it before ... they all ended up pulling out the ether.

Jamison,

Coilhose (http://www.coilhose.com)

cmk

if you can afford it (and if you couldn't you probably woulnd't have oba anyways) run 3/8 lines. not because it definitly helps but cause it can't hurt. at the least you will have a tiny bit more storage capacity due to the increased volume in the system.

Originally posted by cmk
Paul,

I'll be honest with ya' man, you're the first guy I've heard from that has successfully reseated beads with a 1/4" system. I've watched guys try to do it before ... they all ended up pulling out the ether.

Jamison,

Coilhose (http://www.coilhose.com)

cmk

I have seated a 35x14.5" SSR with mine (1/4" fittings, 3/8" rubber hose)

But you need practice I guess :flipoff2: my friend Bob Giroux (Jeepclub on here I believe) has seated several beads with a cigratte lighter socket powered $30 compressor. Including three of my 38x14.5" SX's when we were installing them on the bead locks in my driveway.

He just plugs it in and lifts the tire a bit until it starts to seat.

Phil

Originally posted by 1TONTJ


I have seated a 35x14.5" SSR with mine (1/4" fittings, 3/8" rubber hose)

But you need practice I guess :flipoff2: my friend Bob Giroux (Jeepclub on here I believe) has seated several beads with a cigratte lighter socket powered $30 compressor. Including three of my 38x14.5" SX's when we were installing them on the bead locks in my driveway.

He just plugs it in and lifts the tire a bit until it starts to seat.

Phil


Yup, but I Think's it's because only one side of the tire came off the rim, if both beads came off then I don't think I could do it with the little compressor.

I bought the best 1/2" impact I could find:

IR2131 (http://www.irtools.com/auto/prod/2impact/2impact.htm#IR2131)

and I am not impressed with the power. The manual says to use AT LEAST 3/8" fittings and hose. I have 1/4" and I think that is the problem, so if I was designing and onboard air system, I would go 3/8, especially if it has a reserve tank in the system.

Originally posted by Shrock
The manual says to use AT LEAST 3/8" fittings and hose

How could you use 3/8" fittings with 3/8" hose?

My Husky impact works fine with 1/4" fittings...

Phil

Ok, 3/8" it is.

Now, tell me where I can find British or Metric fittings? Found a tank that fits well in a semi-truck boneyard, but it has 22mm ports. Two of the ports had 22mm to 3/8" bushings in them, so I know they are out there somewhere, but I sure can't find them. Have searched all over the internet. The tag on the tank reads "Stop Fire 27 Bernay (France) PE 20 bar S 10 bar air cap 8L" blah blah blah.

Sound like I'm screwed?

Thanks for the help.

Brand new air brake tanks are $20-$30 at transport places. They come with npt fittings. Doesn't leave much reason for screwing with old rusty metric POS foreign tanks :flipoff2:

Phil
Be cheap only when it is cost effective...

I've also reseated beads with my 1/4" fittings.

On a somewhat related note, does anybody know how much volume 60' of 3/8th's hose would be?

I have 1/4" quick couplers and even that cheesy coiled hose. I've seated many a bead with my OBA and I also use it for impact work in the garage.

I do use ~7 gallon tank at 175 psi. It takes the York about 30 seconds to fill it from 130-175 (130 kicks on the pressure switch) at around 1000 rpms.

I can't see how 3/8 would've made that big of a difference. Plenty of air to get the job done. I too am an engineer so gas flow is nothing new to me.

Originally posted by 1TONTJ
Brand new air brake tanks are $20-$30 at transport places. They come with npt fittings. Doesn't leave much reason for screwing with old rusty metric POS foreign tanks :flipoff2:

Phil
Be cheap only when it is cost effective...

No way. :mad: I haven't found anything close to that. :confused: You got a web site?

I've found plenty of 6"x23?" for $69 or so, but nothing that cheap. I need one 5-6"x18-20" to tuck up behind the winch under the front skid.

Thanks.

Originally posted by raider89


No way. :mad: I haven't found anything close to that. :confused: You got a web site?

I've found plenty of 6"x23?" for $69 or so, but nothing that cheap. I need one 5-6"x18-20" to tuck up behind the winch under the front skid.

Thanks.

Got mine from Malmberg's Truck and Trailer (http://www.malmbergtruck.com/) (I set them up as a sponsor for our Jeep club - so we get "jobber pricing")
Mine is 8x26" I beleive with three npt ports, and cost CDN$30 (about US$20).

Did you try calling your local tranport places out of the yellow pages? Air brake tanks shouldn't cost US$69 unless they are from an on-line 4x4 store :flipoff2:

HTH,
Phil

I got mine for $20 at a big truck junkyard. They had TONS to choose from.

I've found plenty of 6"x23?" for $69 or so, but nothing that cheap. I need one 5-6"x18-20" to tuck up behind the winch under the front skid.


I've said it so many times and I can't believe nobody else has said it yet.

Check a Big Rig shop, Graveyard, or dealer for their air brake tanks. they come in all shapes and sizes with numerous NPT ports and sturdy feet for mounting. They are also rated for 150psi working and can safely hold 175psi (I say that from experience and research)

The best thing is they are cheap (at the right place). I got mine brand new for $10.

1TONTJ - Thanks for the link. I'll try them for the bushings. You guys seem to get some European stuff up there we don't get down here.

bigdude - Ease up:flipoff2: , if you go back and read the post, you'll see that's what I've been doing. That's why nobody has said it. I've been doing it for 4 months now :( . Not complaining about all the time I've spent in the yards (love that), just about not being able to find one that fits the hole I want to fill.

And, the cheapest used tanks I've found in the yards are $35:confused: Things must be different here.

Originally posted by jeepclub



Yup, but I Think's it's because only one side of the tire came off the rim, if both beads came off then I don't think I could do it with the little compressor.

I carry a two inch wide ratcheting tie down strap to get two beads seated. Wrap it around the tire and tighten it until the beads contact the rim. Air up. Take the strap as soon as the beads seat. :eek:

I also run the IR2131 impact wrench. Runs the same whether behind the York or a home system.

Paul

Originally posted by cmk
Paul,

I'll be honest with ya' man, you're the first guy I've heard from that has successfully reseated beads with a 1/4" system. I've watched guys try to do it before ... they all ended up pulling out the ether.

Jamison,

Coilhose (http://www.coilhose.com)

cmk
I did it just a couple days ago, 38.5 SX completely off both inner and outer beads. I have 1/4" fittings and two quick connects, and it reseated the bead with the help of a ratchet strap around the tire, no problem. The 1/4" fittings are going to flow way more air than you can get through the valve stem.

Hey Honkylips, we're in the same area. Which yard did you find one in? It might not be a yard I've been to yet. I don't remember all the names, but they've been in the Commerce City/Brighton areas.

Ah ... I was not aware of the tie dow strap "trick."

cm "learn somethin' new everyday" k

bigdude - Ease up , if you go back and read the post, you'll see that's what I've been doing. That's why nobody has said it. I've been doing it for 4 months now . Not complaining about all the time I've spent in the yards (love that), just about not being able to find one that fits the hole I want to fill.


Send me the dimensions your looking for and I'll check my place. if I find one I'll ship to you. they are pretty light so I'm guessing shipping would be like $10 bucks:D Is that light enough for you:flipoff2:

Originally posted by bigdude


Send me the dimensions your looking for and I'll check my place. if I find one I'll ship to you. they are pretty light so I'm guessing shipping would be like $10 bucks:D Is that light enough for you:flipoff2:

Like sucking helium bigdude! I'll pm ya.

Originally posted by mytzlflick
if you can afford it (and if you couldn't you probably woulnd't have oba anyways) run 3/8 lines. not because it definitly helps but cause it can't hurt. at the least you will have a tiny bit more storage capacity due to the increased volume in the system.

I, too, reseat beads on my 36s with my 1/4" fittings on my York OBA.

Even do it with the cheap 1/4" coil hose! :flipoff2:

I carry two 25' 1/4" coil hoses primarily just for airing up rigs. I also carry a short length of 3/8" rubber hose that's my backup in case the coil hoses both die.

I used to carry a 50' coil, but when it goes, you're done.. so I use two 25' units now.

The two 25' units fit nicely into an ammo can.

Only problem I've had regarding fittings.. on my Scout, I used 1/4" pipe and fittings everywhere. Works great. Turn the hand throttle up and fill those big tires..

On my tow rig, I went with 3/8" pipe and fittings, which goes down to a standard disconnect and then to 3/8" ID hose with 1/4" fittings...

Problem is, there's a restriction somewehre in there - maybe I got some teflon tape covering the quick disconnect or it's just the disconnect fitting itself.. but if I crank up the RPM the compressor fills up the short length of 3/8" piping, hits 125psi, and shuts off.. then kicks right back on.. and the clutch just keeps cycling instead of pushing more air out.

So it fills tires just as fast at idle as it does at 3500rpm.

I need to take it apart and look at it again, I guess. Which is fine.. I have a tank to mount under the pickup box now, anyhow..

Does anyone know where I can get a tank that is rated for 200 PSI? I will be building an OBA system on my dads work truck. He needs to run a "truck gun" and needs atleast 180 PSI.

i was going to run my system on 3/8" fittings, but then i noticed, all my tools and chucks are 1/4", i would want more volume not pressure, so i just ran 1/4" fittings.
and before any of you speak-before-you-think types flame me for the pressure thing, think for a minute, when you run a big hose to a small hole what happens?

Originally posted by RHINO
when you run a big hose to a small hole what happens?

She complains that it hurts?

cm "I get that ALL the time" k

I picked up a 3.9 gal tank (8"x18") and brackets from a local truck yard for $25, rated for 150 psi and has two ports on each end plus a drain port.

http://users.superford.org/ylobronc/onboardair/tankmounted.jpg

LOL cmk, i thought of that right after i wrote it.
yeah truck yards, pete,mack,ect)are the best places to find them.

Originally posted by Benny Boy
Does anyone know where I can get a tank that is rated for 200 PSI? I will be building an OBA system on my dads work truck. He needs to run a "truck gun" and needs atleast 180 PSI.

I have a liquid refrigerant receiver,it's 36"x8"x8" with 5\8 and 3\8 valves.I'm not sure what the tank is rated for but the popoff saftey is 500psi.It also came with mounting feet.
Also have a smaller one 26"x6"x6",it's popoff is also rated at 500psi and it has two different types of mounting feet top and bottom.I got them both from work.Try asking your local a\c companys for used ones.Usually when we replace large condensing units everything gets replaced,compressor\condensor\receiver.You could also ask at a refrigeration supply company.