[Tfrazier]

HI all,
I was messing about in my engine compartment this afternoon after I got back from a short drive. I heard air coming from somewhere so I started looking around. My air dryer is located there and I found that the air was escaping through what might be some sort of release valve on the top on the dryer. I don't know much (anything) about the air dryer so I'm hoping for some in put. I have attach a pic of the air dryer and the valve. Can this be repaired?
       

[bestgenman]

It appears from your picture that this is an overpressure device.  Is your system pressure normal?  If it is normal then it likely has given up its function.  They can be replaced.  A truck supply should have them or online search should find one.

I believe this is a Brakemaster separator but am not sure if they are still around.  They are pretty important to have functioning.  Are you getting water from your tank drains?

[Richard]

Tony,

You might thing about pulling that dryer out and replacing it with a Bendix AD9 or similar.

[Tf175]

That is the pressure relief valve, along with a galvanized pipe fitting that has likely been added to adapt to larger thread size .
I'm with Richard , consider an AD-9 unit and be done with it .
Chris

[Tfrazier]

Thanks for the input guys. Regarding the Bendix AD 9. There seems to be quite the variety to choose from. The actual Bendix units, which are around 500.00 (give or take), reman units (like Haldax) for around 325.00, and Bendix AD 9 "style" air dryers for between 125.00 to 250.00. What to do? I tend to lean toward spending the money and getting a new Bendix unit, but I don't want to waste my money either. What do the Guru's suggest?

Thanks,
Tony

[Tf175]

Local truck shop handles Automann products , I bought their AD 9 version about 3 years ago.  Somewhere in the  $200 range as I recall . Well made , friend was parts man , told me they had sold several with no issues . 
Chris

[Richard]

It's not a nuclear reactor. I would just make sure that whatever I bought used the standard air dryer cartridge.

[Tf175]

Yes , I forgot to mention the Automann uses standard issue cartridges . Prior to rebuilding my compressor , it was venting some oil into the AD -9 . After the rebuild I replaced the cartridge with a Haldex part . 
Chris

[Tfrazier]

Hi all, ended up getting the Bendix AD 9. Was going to order the Automann version but ran across a new Bendix  unit for just a few bucks more. The plan is to install it next weekend and I want to make sure I have everything I need before I start.
Has anyone changed out one of the old  Breakmaster units for the AD9? Anything I need to be aware of it? Any advice or input would be appreciated.

Thanks

[Tf175]

The mounting brackets for the AD 9 have different spacing than the Brakemaster unit . I drilled holes in the lower mount to suit the original treaded holes in bulkhead . Welded a piece with correct hole spacing to the top mount . 
I replaced the steel braided hose from compressor to dryer with a longer one (# 12 , 33") to eliminate a section of pipe and fitting that was on old dryer .
However , I think the original will fit .
The line to governor is 1/4 npt , both units .
The discharge on original dryer is at the top , your AD 9 will be at the bottom , so the existing hose won't reach if like mine . The hose is DOT , 5/8 . I added a new section of hose using a DOT coupler . The AD 9 has 1/2 npt discharge , I used 90 degree DOT fitting to fit the hose . 
I would be interested to know if your model has any plumbing from the purge discharge . My Brakemaster had a copper tube plumbed to the purge and routed to the muffler . I do not believe this was original .
Let me know if you need more information. 
Chris