Why is air backfeeding from my trailer emergency supply line?
My trailer is back feeding through the emergency (red) air line when I set the parking brakes. The air was feeding through my red brake knob on the dash, so I disconnected the red air line and air was pouring out of the trailer gladhand. In addition, when I set the trailer parking brake only, it is slow to apply, by this I mean several seconds from the time I pull the valve until the truck stops rolling. I'm thinking one of the trailer valves would need repair, a friend suggested the dash air valves, as air comes out of the valve as well when it's set.
I have a 2012 GD air ride trailer that has Heindrick air ride suspension. I only have one air tank on the trailer, and a valve in front of it that has a controller on top of it for the ABS system. There is another valve behind the air tank, that I have found some air exhausting out of as well, but seldom does air come out of this valve. Which valve do you think is bad? Do you think I can take it apart, clean it, and put it back on? Or do I need to replace it? What about air system conditioner, isn't that just alcohol? Would that do any good?
OK, what it turned out to be was the air slider button/valve.
All the brake chambers tested good, and the valve did as well. I took it to a mechanic at Cowser Tire & Service, they replaced the service air valve, but that didn't fix it. They had already checked the brake chambers so the said they didn't know what else to do. They had put the new air valve on, and worked on it for a couple of hours, but didn't charge me anything as they weren't able to fix it.
Then I went to Great Dane in Dallas. They said it was the air valve, but Cowser had put on the wrong air valve so GD replaced it again. This still didn't work, they also had checked the brake chambers, so he closed off the air slider hose, which made the brakes work as they should. So they replaced that button, which, the part was $33, and it worked. The total charge was $233.61. They said the valve that was put on was not OEM so that's why it was replaced first, and they had never seen the air slider button/valve cause this problem before. As all the chambers tested good, so the valve was the obvious culprit at that point. All in all, I'm happy with the result, I learned that the air slider valve button, can cause back feed through the emergency glad hand, and how to test it.
Is this a good question?