How the Haldex air dryer works

[tennmogger]

Found this info PDF on the Haldex website:

[edit: see post 4 this thread]

Great info for understanding what goes on in their air dryers as used on the later FMTV's.

Bob

 

[Lmtv772]

Found this info PDF on the Haldex website:

file:///C:/Users/Admin/Downloads/L20463W_Pressure_Swing_Theory_11-02%20(1).pdf

Great info for understanding what goes on in their air dryers as used on the later FMTV's.

Bob

that's a link to your file on your local computer won't let us open it

 

[frank8003]

that's a link to your file on your local computer won't let us open it

I went and got the file but the SS site disallows upload of it. It is 10.4mb
If you want it then email me because we cant send attachments with PM.

 

[juanprado]

http://www.haldex.com/north-america/applications-products/literature/Brake--Suspension-Systems-Literature/Airline--Air-Dryers/


Upload does not appear to be working right. I have also had trouble over the last week on multiple posts....

 

[Plane Fast]

Do you guys know what this part is on the MRAP style air dryer. (Air dryer PART # N50011K) No luck with haldex.


Oh and your link worked good for me.

 

[juanprado]

That is the part number for the entire mrap style air drier and I think the lmtv a1's also use it.

Many have retrofitted to m939's.

 

[Plane Fast]

I have this one on my truck. I'm trying to figure out what the brass valve does. It's not the relief valve or the purge valve.


haha sorry I just realized I did not load the pic!

 

[juanprado]

check out the specs:
http://epi.hbsna.com/products/dept....E86A8CE400AE0887E&dept_id=2749&parent_id=3191

 

[Plane Fast]

check out the specs:
http://epi.hbsna.com/products/dept....E86A8CE400AE0887E&dept_id=2749&parent_id=3191

Yeah I went through their whole website earlier. Not one spec on that part.

 

[juanprado]

N50011K is the "OE" part number haldex uses for the military application not the haldex aftermarket part number.

 

[tennmogger]

that's a link to your file on your local computer won't let us open it

Oops, red face. Thanks for pointing that out, and thanks for the good link. I edited the original post to avoid wild-goose chases.

Bob

 

[juanprado]

View attachment 605086Do you guys know what this part is on the MRAP style air dryer. (Air dryer PART # N50011K) No luck with haldex.


Oh and your link worked good for me.

That looks like the outlet port with a brass push to connect quick fitting for the nylon air tubing?

 

[Plane Fast]

No. It's some kind of valve. The inlet and outlet ports are defined, and the overpressure valve is on the side. So I'm not sure what the part does. It started chuffing air this week. I though the purge valve was sticking, but it was working correct. The secondary purge is coming from this valve. It only does it with the first air up of the system and sometimes after long brake applications. At first I thought the system was over-pressurizing and the relief valve was opening. It was not, just dumping air out this valve. It does it in a quick succession four or five burst, then stops.

 

[juanprado]

I would call haldex tech support. I have found them very helpful in my past life selling parts...

http://www.haldex.com/en/north-america/Tech-Support/Live-Support/

 

[Plane Fast]

I have few extra air dryers. I'm going to take one apart as well. Maybe take some pics. A lot of use have these on our trucks now.

 

[Lmtv772]

That is the part number for the entire mrap style air drier and I think the lmtv a1's also use it.

Many have retrofitted to m939's.

that's the one I have on my M1078

 

[Plane Fast]

Well this is concerning! I pull that brass valve, and indeed its a pressure relief valve. The only problem it opens at 235 psi!

On top of that, the normal pressure relief valve show signs of opening. (150 psi) ((grease had sprayed out on the case))


The only thing is the gauges show normal 120 to 125 psi. There is no air leaking after it does this little secondary purge.
I have a new govenor and a PPV I can put on if needed.