Replacing air tank

[Trevronious]

Hey y’all, wanting to replace the air tank on our bus as ours currently has a pinhole leak.

I’m having trouble understanding exactly how the tank seems to work and where to find a good replacement. Ours currently looks to have at least two if not three separate chambers and I can’t find an exact replacement. Do I need to get something that’s exactly the same size and dimensions/chambers? Or can I get multiple tanks and plumb them in a particular order? We have a dryer on our bus so hopefully that helps alleviate some issues.

Considering it’s a pretty important part of, well, everything I’m really not wanting to start guessing.

[o1marc]

Go to the UserCP and fill out your profile so we know what bus you're working on.
Ya, you don't want to guess with this stuff, brakes are kinda important.

[Brad_SwiftFur]

Originally Posted by Trevronious

... Ours currently looks to have at least two if not three separate chambers and I can’t find an exact replacement. Do I need to get something that’s exactly the same size and dimensions/chambers? Or can I get multiple tanks and plumb them in a particular order? We have a dryer on our bus so hopefully that helps alleviate some issues.

Considering it’s a pretty important part of, well, everything I’m really not wanting to start guessing.

Air systems typically have a "Wet" tank, "Primary" and "Secondary" tanks (occasionally an "Auxiliary" tank). Air heads to the "Wet" tank first where moisture will condense (even on systems with an air dryer). Sometimes air systems will in fact be one physical tank with multiple reservoirs/chambers.


Here's the good thing. You can, in fact, replace it with something close in size/capacity, it doesn't have to be a perfect match. You can add larger tanks if you choose (I would try to avoid going much smaller), either combination tanks or separate ones, as you see fit.


There are valves to equalize the system but also serve as protection should one system suddenly depressurize, one is commonly known as the "Protection" valve, which opens around 60 PSI or so. Many of your air accessories will be on the protected side (Pretty much everything except the brakes, which get full pressure at all times regardless how much/little there is).


Personally I like pretty shiny aluminum tanks and they won't rust, but they can be a bit pricey.

[PatrickBaptist]

Welcome to the forum. Goto the CP and fill out your info so we know what bus you have and all.
Don't feel bad, mine is rusted good and will have to replace it as well before long.
Brad_SwiftFur is correct in what he said.

[Trevronious]

Originally Posted by Brad_SwiftFur

Air systems typically have a "Wet" tank, "Primary" and "Secondary" tanks (occasionally an "Auxiliary" tank). Air heads to the "Wet" tank first where moisture will condense (even on systems with an air dryer). Sometimes air systems will in fact be one physical tank with multiple reservoirs/chambers.


Here's the good thing. You can, in fact, replace it with something close in size/capacity, it doesn't have to be a perfect match. You can add larger tanks if you choose (I would try to avoid going much smaller), either combination tanks or separate ones, as you see fit.


There are valves to equalize the system but also serve as protection should one system suddenly depressurize, one is commonly known as the "Protection" valve, which opens around 60 PSI or so. Many of your air accessories will be on the protected side (Pretty much everything except the brakes, which get full pressure at all times regardless how much/little there is).


Personally I like pretty shiny aluminum tanks and they won't rust, but they can be a bit pricey.

Sorry for the lack of bus info, thought that was all already in there lol. I'd love to just get the same tank but I can't find a single one that seems even close to my current.

But that is super helpful, thank you! So I shouldn't have any issues replacing my one big tank with two (three would be unnecessary?) similarly sized tanks? Also I'm assuming a protection valve is already in place somewhere along the line so I shouldn't have to worry about that?

Would there be anything crazy different as far as the plumbing goes with two or three tanks? Guessing as long as they're all attached accordingly everything should work. I always figured the air gauge in the dash, having two arrows, was each respective chamber of the tank so my biggest fear was replacing it and one of them not working properly or something.

Appreciate the info!

[Brad_SwiftFur]

Originally Posted by Trevronious

Sorry for the lack of bus info, thought that was all already in there lol. I'd love to just get the same tank but I can't find a single one that seems even close to my current.

But that is super helpful, thank you! So I shouldn't have any issues replacing my one big tank with two (three would be unnecessary?) similarly sized tanks? Also I'm assuming a protection valve is already in place somewhere along the line so I shouldn't have to worry about that?

Would there be anything crazy different as far as the plumbing goes with two or three tanks? Guessing as long as they're all attached accordingly everything should work. I always figured the air gauge in the dash, having two arrows, was each respective chamber of the tank so my biggest fear was replacing it and one of them not working properly or something.

Appreciate the info!

As a rule you'll want to duplicate what the factory did with 3 tanks/compartments, for the Wet, Primary and Secondary, either with compartmented or multiple tanks. Keep in mind, manufacturers are frugal and they don't just put on multiple tanks/compartments (which costs money) without a good reason if a single one would otherwise suffice. There's 2 systems (primary/secondary) *FOR A CRITICALLY IMPORTANT REASON* - if one system suddenly depressurizes, the other maintains air pressure so you can at least safely stop. That's the entire purpose of the various valves - the Protection valve and (I don't remember the proper name of the other one. Balancing valve? Equalizing valve? Something like that) Basically this valve allows both tanks to fill and maintain similar pressures, and discharge at about the same rate, but it's also supposed to remain closed should one side depressurize quickly so the other side stays pressurized.


Whether you use 3 individual tanks, compartmented tanks or some mix thereof (the "form factor" isn't important, the function factor is), I do highly recommend duplicating what the factory did so the system will continue the way it was engineered to. You *WILL* need to make sure all tanks have drains and I much prefer either automatic drains or the "cable-pull" drains (A quick tug will open the valve, allowing air and whatever collected moisture to escape. This should be done at least once a day it is driven.) The Wet tank will collect the most moisture even with an air dryer, this is the one I'd recommend an automatic drain on (many systems have an automatic air purge with usually cycles whenever the air compressor cuts out).

[Booyah45828]

Originally Posted by Trevronious

Hey y’all, wanting to replace the air tank on our bus as ours currently has a pinhole leak.

I’m having trouble understanding exactly how the tank seems to work and where to find a good replacement. Ours currently looks to have at least two if not three separate chambers and I can’t find an exact replacement. Do I need to get something that’s exactly the same size and dimensions/chambers? Or can I get multiple tanks and plumb them in a particular order? We have a dryer on our bus so hopefully that helps alleviate some issues.

Considering it’s a pretty important part of, well, everything I’m really not wanting to start guessing.

Call a bluebird dealer, give them your body # located on the build placard, and get one identical to what you have. You can have them give you the part number if you'd like to price shop online.

Biggest thing about plumbing multiple tanks is it will likely take up more room under the bus, and you'll have to get more bracketry, hoses, couplers, etc. making it likely more expensive then what you have. You'll need 3 tanks minimum, and make sure you get the check valves between them too. If you're going to go down this road, read up on air brake system operation so you don't mess anything up.

[Brad_SwiftFur]

As an aside, when redoing the air system, there's no reason you can't add an air disconnect for using air tools and inflating tires. I would add this on the "protected" end of the circuit, and/or a cut off valve at/near the tank if not on the protected side.


Also feel free to eliminate the quick-connect fittings (which are prone to leakage with some age) and replace with widely available compression fittings. Do use the inner bushings on each connection if you do this, however.

[Johnny Mullet]

Just to throw this out there, but an air tank can be welded/repaired safely, BUT commercial, DOT, and certain state inspections don't allow it by law. Some of these laws don't apply to farm, offroad, or private equipment.

[Brad_SwiftFur]

Originally Posted by Johnny Mullet

Just to throw this out there, but an air tank can be welded/repaired safely, BUT commercial, DOT, and certain state inspections don't allow it by law. Some of these laws don't apply to farm, offroad, or private equipment.

Personally I wouldn't feel comfortable with a welded-patched air tank, at least not for any long term use, but I would in a pinch to complete a road trip.

[cadillackid]

does the bus have an Air dryer? if not I would consider adding one.. water in the tanks is a good reason for tanks to rust from the inside out and leak.. Air dryers dry the air even before it goes to the wet tank. and you have lot less issues.. not to mention a heated air dryer is a MUST if you are travelling in the below-freezing winter weather..
-Christopher

[Trevronious]

Originally Posted by cadillackid

does the bus have an Air dryer? if not I would consider adding one.. water in the tanks is a good reason for tanks to rust from the inside out and leak.. Air dryers dry the air even before it goes to the wet tank. and you have lot less issues.. not to mention a heated air dryer is a MUST if you are travelling in the below-freezing winter weather..
-Christopher

It does! The bus is from Ohio, hence the rust issue, so it seems pretty well equipped for winter driving even though I'm in FL. The cartridge is probably overdue for a change speaking of. Looks pretty easy to swap out if I can get it off.


It also seems the eBay gods have been on my side lately, searched up the part number and managed to find a brand new factory tank on there up for auction. Turns out not a lot of people are needing one of these (go figure) as I got it for $99! Only bidder. Seen others going for around $7-800.

Picked up a new air seat on there too, same Bostrom that came from the factory. A lot of people seem to not like them but I thought the ride was pretty good on the way home. Didn't wan't to worry about new mounting/plumbing issues and it bolted right up.

[Johnny Mullet]

Great score!