Air dryer issues - Best replacement for AD2

[bs4104]

Question? The old GM's 04s,06s never had a dryer. With the short trip we run, & not running every day do we need a dryer--Then why not just drain your tanks daily when park? Bruce

[Geoff]

Of course you don't need an air dryer if you drain your air tanks after every run.  Its just a convenience.  I like hearing my AD-9 blow off when the air pressure is up. Lets me know the pressure is up and the crap is being dumped.

--Geoff

[Seangie]

So I ended up going with the ADIP.   Its the same technology as the AD9 but like Cliffy said its an easy job to change out the dessicant cartridge.

Only took a couple pics as we were pressed with time to get it done. 



The supply line was old, crusty, rusty and dusty.  We kinked it trying to get it off the old dryer.  We ended up just cutting it out and will go pick up a new one tomorrow.   Hopefully its something readily available.

Does anyone know what the minimum length of supply line is?  Our air dryer is only 4' from the compressor.  The previous airline was about 20' long and coiled up on a tray before going to the dryer.

this is the tray the supply line is laid out on.

almost finished install.  Just need a supply line.

Thanks Guys.

-Sean

[luvrbus]

My instructions say 9 ft for 1/2 inch pipe you are going to like the ADIP

[Oonrahnjay]

    I did things a little differently (now, there's a shock, I hear you say).  I used the new AD-IS dryer.  You have to redesign and rebuild the brake system on your bus but I had to anyway.  Every system is isolated and supplied with air separately.  It can also be adapted for "Discharge Line Unloader" type governor (if you don't know, don't worry about it -- just be glad that you had the smarts to buy a N. American-built bus). 

[Boomer]

The copper cooling loop is there to pre-cool the air Sean and should be left in place if you can.  The discharge line before the cooling loop is special and also should be left, or replaced with like.

[eagle19952]

For that location I would have chosen what you did too. 

[Jim Eh.]

Just wind some copper line around a large(r) diameter tube, something open ended 
You may need to carry a schematic for when you get pulled over and have to explain that it is NOT a still!

[Seangie]

The copper cooling loop is there to pre-cool the air Sean and should be left in place if you can.  The discharge line before the cooling loop is special and also should be left, or replaced with like.

Boomer,

I'm going to replace the entire line and rerun the new line the same way including the loop.  I wish I could just leave it as is but I don't have a torch or big tools where I'm at and the connectors are pretty frozen.  I figure for the cost of my time (and frustration) its going to be easier just replacing the line.

There is no copper though.  Not that I can see.  Its just the 20' braided plastic line that runs the loop.  Looks like 6' sections of Bendix Air Compressor Discharge hose assembly (part 142572)

In the picture its just covered in a good 1/8" layer of dust and grease but that definitely isn't copper.

Thanks guys.

-Sean

[belfert]

There has got to be some other way to replace that discharge line other than buying three of the Bendix discharge hoses at $70 or $80 each.  I don't recall what my bus uses.  Could a hose shop like Pirtek make up something?

[Boomer]

From the factory, the serpintine copper cooling loop was attached to the mounting plate above the rear end by a whole bunch of wire clamps.  Maybe someone drilled a hole in it or something rubbed a hole in it and that was their easy fix.  I had to remove the whole plate and loop when I put the air ride on the back of my Eagle and wound up with about 10' of braided line.  You'll be fine.  That design was for the old AD-2. They didn't even use the copper loop until the Model 10. When I did what you did and put an AD-9 on mine there wasn't enough room in the compartment so I had to move the forward part of the fiberglass closing panel ahead about 2" (above the mud flap).

[Jim Eh.]

Different manufacturers spec different total lengths of copper, teflon, or combination of both but like it has been said "around" 10'. The reason for the length of the line is to reduce the compressor discharge air temperature < 160 F before the dryer.
Also make sure you do not introduce a low spot in the line assembly. Any low spot can collect enough moisture that if you ever get into freezing weather can block the compressor discharge line and your compressor will reeealy not like that.

[Seangie]

So here is what I ended up with.  There was a hose supply shop next to the ttriple-t and they happened to sell the reuseable ends for the wire-braided Teflon tubing.  So I ended up with a new end on the line and just added a 3' section to reach the dryer.  Ended up being a lot easier than I thought it would be. 

Definitely a noticeable difference wth the new air drier.  It purges a lot less now.    At idle its more then 10 minutes...I stopped counting after 8.  Its a nice clean quick purge and I think the air holds longer now.  I had a few issues with my AD2 and its been on the list to replace for a while now.  Glad that I did.

Thanks all. 

-Sean

[buswarrior]

To round out the thread, the reason for minimum runs between the compressor and air drier is to protect the desicant in the drier. Heat is a desicant killer.

I concur, run your length of piping in a continuous downhill direction so there is no pooling of condensate moisture. It goes below freezing EVERYWHERE in the continental US eventually...

Happy coaching!
buswarrior

[solodon]

OK, after reading this, since I'm still a newbie, when I hear air blow off under the front at 120 psi, it's an air dryer  blowing off?