Bendix AD-9 mystery valve

[Iceni John]

I replaced my old AD-9 today with a new AD-9, and I noticed that the old one has what seems to be a valve above its discharge port that connects to the wet tank.   The new AD-9 has no such valve: its discharge line connects directly to a 1/2" port in the aluminum lower casting, while the old AD-9 has a stepped adapter fitting into the casting and the line then attaches to this adapter piece.   The new AD-9 works perfectly, so what was the reason for the extra valve in the old AD-9?   The new AD-9 is version 065225, but I don't know the version number of the old AD-9.   Just curious.

Thanks, John

[luvrbus]

Are you sure the drier you replaced wasn't a AD-4 ?,the 4 is the only drier I saw with the valve

[Iceni John]

No, it's an AD-9, albeit a very old one.   I wondering if the mystery thing is a check valve, and if it is I suppose I could add an external CV if I need to, but at this point everything is working as it should.   There is a check valve already at the wet tank, but I don't know if it's sealing shut correctly or not;  it's very hard to reach, so if it's not working right I'll just add another CV somewhere else.

[luvrbus]

If the dryer is OEM it could be a little iffy being a AD-9 since they 1st hit the market in 1989 or 90 with the AD-9 ,not saying yours is not a AD-9 but I have changed out a lot of the AD-4 in the past on 1991 year model buses that were OEM

[sledhead]

I just replaced my AD9 with a rebuilt AD9 that was rebuilt in mexico
For $242 + $265 for the core change ?
So in the end it was $242 + tax
Identical as the old Bendix

Sounds to cheap to me

[luvrbus]

I just replaced my AD9 with a rebuilt AD9 that was rebuilt in mexico
For $242 + $265 for the core change ?
So in the end it was $242 + tax
Identical as the old Bendix

Sounds to cheap to me

The Chinese knock off AD-9 for less than 300 bucks are not that bad of drier, I have installed several of those the last few years lot of people want new a Bendix AD-9's till they find out the price they are not cheap

[Iceni John]

The Chinese knock off AD-9 for less than 300 bucks are not that bad of drier, I have installed several of those the last few years lot of people want new a Bendix AD-9's till they find out the price they are not cheap

I paid $375 for my brand-new and still-in-the-original-box Bendix, the lowest price I've seen for one.   Its paint was scuffed, but otherwise it's perfect.   I just wait until a good deal shows up, then I pounce.   I bought a brand-new Leece-Neville 160A alternator for less than the price of a Chinese/Brazilian/etc knockoff copy, so the bargains are out there, but just not very often.   Yes, a Chinese copy AD-9 is probably just fine for me, but if I can get a new Bendix for a good price, then why not?   I prefer to keep with real USA-made parts wherever possible, for peace of mind if nothing else.   My old AD-9 was still working, but something's not right with its purge process and the dessicant is saturated with oil, so now I have a new dryer to go with my rebuilt compressor.

John       

[Van]

I paid $375 for my brand-new and still-in-the-original-box Bendix, the lowest price I've seen for one.   Its paint was scuffed, but otherwise it's perfect.   I just wait until a good deal shows up, then I pounce.   I bought a brand-new Leece-Neville 160A alternator for less than the price of a Chinese/Brazilian/etc knockoff copy, so the bargains are out there, but just not very often.   Yes, a Chinese copy AD-9 is probably just fine for me, but if I can get a new Bendix for a good price, then why not?   I prefer to keep with real USA-made parts wherever possible, for peace of mind if nothing else.   My old AD-9 was still working, but something's not right with its purge process and the dessicant is saturated with oil, so now I have a new dryer to go with my rebuilt compressor.

John       

Be sure to keep your old 9, there are plenty of bargains on new purge kits and new dessicant cartridges kits to rebuild your old one and have handy up on the shelf.😉

Van