Dana Diagnostic tool

[Suprman]

The air dryer is due for service. At least replace the cartridge. The air compressor unloader is a common fault. The lube in there hardens up from sitting over time in the hot sun. A rebuild kit is available and you don’t have to remove the compressor to do it.

 

[319cssb]

ok. so how is the Air Dryer cartridge being replaced? Do I need special tool for that? Have you done that job before?

 

[Suprman]

4 bolts on the metal top cover. Cartridge under the cover. New o ring included with the new cartridge. Takes a few min to do. Get a new cartridge not one that’s been sitting on a shelf for years. I do mine every 2 years.

 

[319cssb]

How does the cartridge get removed from the cover. 4 bolts are off.

 

[Suprman]

4 bolts hold the cover on the cartridge is held in place by the pressure of the cover over the base. Search haldex purest cartridge replacement. Very common air dryer used on tons of civilian applications in addition to military.

 

[319cssb]

4 bolts hold the cover on the cartridge is held in place by the pressure of the cover over the base. Search haldex purest cartridge replacement. Very common air dryer used on tons of civilian applications in addition to military.

Filter cartridge was stuck in there. The warning that it's spring loaded had me kind of confused. after a bunch of shaking and such it came out.

 

[Suprman]

Usually one waits till they have the replacement filter in hand before removing the old one.

 

[319cssb]

Parts get here pretty fast. I want to see if I really need one. The cartridge was stuck pretty goo and there was some goo in there. So It could be the air dryer , what's causing it.

 

[Suprman]

I have seen cartridges get clogged up and restrict air flow. With the new cartridge installed you want to run the pressure up and drain the tanks a bunch of times. Cycle the brake pedal a bunch. Really try to get as much moisture out of the system.

 

[319cssb]

I have seen cartridges get clogged up and restrict air flow. With the new cartridge installed you want to run the pressure up and drain the tanks a bunch of times. Cycle the brake pedal a bunch. Really try to get as much moisture out of the system.

Hooah!!!
Maybe that will alleviate the intermittent up and down on the front PSI gauge I've been seeing.

 

[319cssb]

New air dryer cartridge. Turned governor screw out a lot.

Pressure doesn't raise. ~90psi.
ctis PSU pressure is a bit lower.
Cycling air and pushing brake pedal. Drained tanks a few times.

P>S> the CTIS starts it's magic at around 70PSI.

 

[Suprman]

You should only have to turn the governor screw 1/4 turn. May be the compressor unloader needs to be rebuilt or there is an issue with the governor. I would lean towards the air compressor though.

 

[319cssb]

Well the CTIS is fixed. I know online diagnostics is a difficult business. However it was a leak inside the CTIS valve block, not the governor or the Air compressor or the Air Dryer. But I guess it was still a good idea to replace the Air dryer filter cartridge inside the air Dryer. without Diagnostic tools, this would have been impossible to fix. I guess thats why the Army gave up on it.

 

[Suprman]

What was the issue? You said you were only getting 90psi air supply. I thought that was what you were working on fixing. Then once you had a good 125psi air supply you would start working on the ctis.

 

[319cssb]

The valve block had an internal leak , that would cause the air pressure to drop on a hurry. Once that was fixed the pressure stabilized.

 

[coachgeo]

The valve block had an internal leak , that would cause the air pressure to drop on a hurry. Once that was fixed the pressure stabilized.

If you would please can you pull a diagram out of the TM or elsewhere and point out what you refer to as the "CTIS valve block"