No Air Pressure??

[Roger Milne]

Thankfully broke down in a camp site but between Arizona and South Carolina.
Pulled in last night and this morning I’ve got no air pressure.
Tanks won’t recharge and obviously Park Brake won’t release.
Where should I start trouble shooting? Is this an air compressor issue or air governor?
Any help on Easter Sunday LOL would be helpful.

[Frank Bergamo]

I would look at the air governor first. They are cheap and can be found at any NAPA or truck place.
https://www.napaonline.com/en/p/BNDBENOR275491X?srsltid=AfmBOopTf_e_N9aDErTU0dxEAmegEjE49t_dqFghb9TdQ5ydIgb8_MLPBeA
Good luck, hope this helps.

[Roger Milne]

Ok. Good to know. Apparently the local NAPA store here in Van Horn has one but is closed until tomorrow. Will go that route first thing in the morning.

[Eric Maclean Co-Admin]

Roger
This might help you understand and troubleshoot the governor, compressor and air drier.

https://youtu.be/bmgSwSeLk_o?si=Whx7W1D9RPOiNeEP

Eric

[Roger Milne]

Sorry for the delay in replying been a busy few days driving.

But wanted to update the situation and get some feedback. So managed to find a mechanic to come out on Easter Sunday and trouble shoot the air system. We found a substantial leak on the back of the air dryer body and we cobbled together a bypass for that and immediately started building pressure again. The only side effect was the air hammering the supply tank as it charged but stops when it hit max pressure. Sounds like someone tapping on the tank with a metal hammer but it does the job.

So now we have reached our destination and I can get some tools I’m gonna pull the air dryer body off and see where the leak is coming from. Then track down a replacement.
But doing this has uncovered another issue. So it appears I have a line leak in the rear right somewhere else as the tanks fill and discharge and as soon as I shut off the engine the back rear bleeds the tanks to zero over night. So that’ll have to be investigated as well.

So I appreciate everyone’s advice and videos etc. and will post another update when I get the air dryer off and see what’s up with that.

[Eric Maclean Co-Admin]

Roger
With your air drier it is often cheaper to buy a complete rebuilt unit than it is to buy individual parts to repair one.
Do you know which model and make the air dryer is.
If you have a haldex pure air plus like the one in the link below and decide to change the filter cartridge try to get it loosened before you remove the unit from the vehicle chassis as they can be seized on and take a lot of torque to get them to come loose.



https://www.anythingtruck.com/product/052-170DA33100.html

Hope this helps
Eric

[Roger Milne]

Roger
With your air drier it is often cheaper to buy a complete rebuilt unit than it is to buy individual parts to repair one.
Do you know which model and make the air dryer is.
If you have a haldex pure air plus like the one in the link below and decide to change the filter cartridge try to get it loosened before you remove the unit from the vehicle chassis as they can be seized on and take a lot of torque to get them to come loose.

Hey Eric,

Thanks for the reply.
Yeah we only reached or new RV home base yesterday and will be here for at least the next couple months while we search for a home. But to answer your question, No that doesn't seem to be the same style. I'll take a pic of it in a little bit and post it but it is at least accessible as it's right in the rear engine compartment by the door and I will remove the cartridge before hand as I agree trying to remove that after the body is off would be troublesome. I can't for the life of me figure out why the body would just start to leak, but removal will hopefully reveal what failed and then the search for the replacement will begin.

[Richard Davis]

Roger
Considering the age of your coach, I suspect your air dryer is a Wabco 1200 series.  Be aware that there are LOTS of generic after-market knock-offs of this dryer that sell very cheap ($50 to $100).  Some have had success with them, others have been disappointed.  The actual Wabco dryer is very expensive.  So, be forwarned when you are shopping.

[Roger Milne]

Roger
Considering the age of your coach, I suspect your air dryer is a Wabco 1200 series.  Be aware that there are LOTS of generic after-market knock-offs of this dryer that sell very cheap ($50 to $100).  Some have had success with them, others have been disappointed.  The actual Wabco dryer is very expensive.  So, be forwarned when you are shopping.

That is a fascinating reply because I actually just got off the Webco webpage looking at one and yes it is a 1200 series and they run about 550 bucks and the same looking model I hadn’t looked at the exact part number but are on Amazon for about 80 to 100 bucks so very good to know thank you for the heads up

[Eric Maclean Co-Admin]

Roger
Here is the service sheet for the 1200 series wabco dryer it might help you determine where or what is leaking..

https://www.wabco-customercentre.com/catalog/docs/mm34_web.pdf

Eric

[Roger Milne]

Thanks Eric, I was actually going to put it back together and run it so I can try and determine where the leak is. It was a "in the field" repair, so I knew it was leaking, but not exactly where. This link might actually help.