Shareing Blu/Dot air with air ride axels?

[oletimer]

I have a Blu/Dot brake controller plus air ride on my 5th, and somewhere I read about using the truck air for both, but I can't seem to find where. Even if I used both tanks in the trailer, I would like to use the truck air for both so as not to have to use the small electric compressor for the ride. I'm sure there is a way to do that safely, but don't know how? Any ideas? Thanks, Dick T

[SIBERNUT]

Understand the system. If you have Bludot brakes (air over hydraulic), the air tank in the trailer is always charged. If you LOSE air pressure from the truck, the slide valve applies the air in that tank to put on the brakes in the trailer. Now, I suppose you could connect your air ride to that, but if the air ride loses air suddenly, you would be unprotected in event of a breakaway.

[bigstick]

What if you ran another line to the air ride on the trailer, using a seperate line (not connected to the brake system)? You could even plumb in a seperate tank on the truck , with check valves (so it would not be connected to braking system) Put a quick connect fitting on it so it cant be confused as a brake line?

[Jack Mayer]

You can do it if you protect the brake system with a check valve. Really, it is pretty simple. You just want to make sure that if something in the suspension causes loss of air in that system that you do not affect the brake system.

[SIBERNUT]

The check valve would not work, it would be 'checking' the wrong way. You would WANT the air to flow to the suspension thru any check valve.

[HERO Maker]

I am also considering this (if I can keep my rig - still waiting on Ins. co.) and was thinking about putting a TPMS onto my air suspension schrader (sp) valve, so I would know if I've blown one of the 6 bags. I'm thinking that Dexter can tell me if I would only be measuring air pressure in the line from the Leveling valve to the bags.

Would like to do this to help inflate suspension quicker, and with clean air. Saves the leveling valve from getting corroded, and failing.

[HERO Maker]

Bill, that looks like the way to go! Just put it on the main tank line going to the suspension tank. Sounds as if the suspension tank is losing air quickly (will need to figure that amount out), and if I have a monitor on leveler valve line, I should have no problem or brake problem with these.

 

Heck of a time trying to find purchase location and price!

[Jack Mayer]

Ron, you are correct. You need a protection valve, not a check valve. References above will work. And for sure I would put a TPMS sensor on it.

[Scrap]

If air suspension has its own tank you put a pressure protected check (ala Bendix PR-3) in the brake tank and plumb 3/8 purple from it to feed your suspension tank. If air suspension shares the same tank as the brakes then you use a normal pressure protection valve ala Bendix PR-4 or one of the bigger GT/Velvac (ala 032219) valves that threads right in and plumbs to leveling valve.

 

If you want the trailer to kneel everytime you park (ie: anti swaying when you walk into it, or anti-can't ever forget to dump suspension before leveling trailer) you get another one of your Sealco pilot valves and plumb like this:

 

[oletimer]

Thanks guys, I will try to digest all this in the near future. It seems I have so many projects right now my feeble brain is on overload. BTW, is there a valve to correct THAT?? I will work through this, but like I've said before, I'm old, slow, and dumb. As always, the knowledge on this site amazes, and humbles me!! Dick T

[Scrap]

Wow rereading and I messed that up this morning. PR-3 mounts into the suspension reservoir, not the brake one. Had myself backwards.

[HERO Maker]

OK Scrap, now I'm pretty sure I'm really confused!

I was agreeing with your first statement that I wanted a protection valve between my brake tank and my suspension tank! If I were to blow a bag, or something snagged a line, the alarm would go off from the monitor, and I would be using the rest of the air in the suspension tank to try and maintain suspension, while I am looking for a spot to pull over and have all brakes on the trailer to do it with because of the protection valve on the brake tank.

 

But if you now say to put it after the suspension tank, wouldn't that just shut down all air to suspension and leave me riding pretty low? And riding low for me is really just setting on the frame. On edit, (I should have said the frame would be setting on the axles.) Yes, I would still have brakes, but don't I want that air in the suspension tank?

 

And yes, I bleed down the suspension before leveling the rig.

 

And I'm really not sure about where the leveling valve is on your diagram? Does the air pass through your pilot valve and then go to both the bags and the level valve?

 

To me that leveling valve needs to be right before those bags, but I don't have the knowledge that you do, plus mine is a 10 year old setup that even Dexter doesn't show anymore!

 

I'm probably not reading your single tank diagram correctly.

 

Thanks.

[Scrap]

PR-3 goes on the suspension tank but it is still the inlet. So the arrow points towards the tank and it makes the check part of it all work just like the supply to two service tanks of your truck. The whole tank is also pressure protected but that doesn't make much difference to the suspension.

 

The diagram is actually Sealco's, but the pilot goes on the outlet line of the leveling valve (between valve and bags). So the pilot will exhaust the bags but it also exhausts the tank through the leveling valve to the pressure protect setpoint. Probably not the most efficient use of air but you don't have to buy a new leveling valve. You are right in that it will only work with the single tank system because the pressure protect is in the outlet. For dual tank you are probably best putting in a valve with a dump port and plumbing that in there instead.

 

Sealco also makes a manual valve that will dump it but also auto resets the next time you charge the trailer. That way you don't have to sit there and hold the pull cable until the trailer finally goes down. I'll dig it and a diagram up later this morning. They also have a suspension priority valve that will fill suspension before brakes if that is a wish or a need. There are so many ways to go with this when you aren't bound by 121!

[HERO Maker]

Thanks Scrap. I'm actually understanding this!

Thanks again for being a major help here on the forum.

Looking forward to working out just which way I will go. But certainly need to get truck air into suspension system.