Tap the Air Brake system?

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jd_is_me

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On a recent trip, one of the tires (22.5x) had a slow leak.? Had a terrible time finding convenient places to add air (normal pressure is ~100#)..most places don't have compressors that go that high.? Someone in one of the campgrounds suggested tapping into the onboard air brake system to have an outlet to attach an airhose when these things arise.? The MH has airbrakes? and also air bag suspension. After a quick look, I could find two air tanks; I assume one for the primary (rear) and one for the secondary (front) brakes?? ?

Anyone had any experience in doing this?? How are the air bags hooked in?
 

John From Detroit

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The job may be easier than you think... MANY RV's with Air brakes have a fitting in one of the basement compartments, Usually one of the front compartmtnts.  All you need is a matching fitting and with a hose and tire chuck (Truck type) on the end,

I like the dual chucks with built in pressure guage myself

Secon:My rig is a Gas Buggy, so no air brakes.... I have a small compressor in one bay and a bigger one in the towed

So far, i've had to use the big one a number of times (The small one is trashcan bound, it's a POS)

BTW. I have used those compressors many times... Usually not for my tires.

Third:  Even if there is no fitting pre-installed, there is usually a manafold somewhere with a spare plug in it where one can be added, Most semi trucks are equiped this way, Most truck service places, camping world, and many RVers know how to hook into thiese fittings,  I believe I do, I know my brother does (He's certified to do it in fact, I'm not)  It is very easy job.
 

jd_is_me

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Aug 3, 2005
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It's a 37' Tropical on Freightliner chassis, 350 CAT.? I've looked for a manifold underneath but don't quite know what I'm looking for.
 

Ned

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Freightliner puts a manifold on the firewall.  It has 7 ports, one is usually used for the air horns.  It will have allen screws in the available ports.  I have added a quick connect fitting to one port to attach an air hose that will reach all of my tires.  Drain the air tanks before removing the screw or you'll get a BIG surprise when it comes out at 100+psi :)  There is a check valve that prevents total air loss but it's still risky to do it under pressure.  I know, I've done it :)
 

jd_is_me

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Ned said:
Freightliner puts a manifold on the firewall.? It has 7 ports, one is usually used for the air horns.? It will have allen screws in the available ports.? I have added a quick connect fitting to one port to attach an air hose that will reach all of my tires.? Drain the air tanks before removing the screw or you'll get a BIG surprise when it comes out at 100+psi :)? There is a check valve that prevents total air loss but it's still risky to do it under pressure.? I know, I've done it :)

Ned, thanks.  What does this manifold look like?  When you say "firewall" you mean it's up front accessable from the generator access door?  Also, how do the air bags work in this system?  I can only find two air tanks and looks like one may be for brakes and the other for air bags....which is different than what I would have expected.
 

Ned

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I don't have a picture, but it's about 6" tall and is roughly cylindrical.  There is probably one air line attached to it for the air horns.  Yes, it's accessible from the generator compartment, unless National moved it, but that's not likely.

The air bags aren't attached to this manifold, they are connected elsehwhere.  The two air tanks are for the primary and secondary air brake systems.  I believe the air bags are connected to the secondary air system.
 

jd_is_me

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Great!  Found it!  National put a small compartment, first one on the drivers side.... for many of the electricals....fuses, conector panels, etc.  The manifold is in there....geez, couldn't be easier.  Thanks for the help.
 

Ned

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Glad you found it.  Just be sure to follow my cautions before you try hooking up to it.
 

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