Air pressure issues

Me and the hubby are company drivers. We don't own our truck but I like to try to learn things about the truck. So we pick up regular 53' trailers, dry bed. Nothing special. Most of the trailers are new-ish and don't give us too much of a problem. The last few trips we have gotten trailers that were obviously older. PTI all checked out fine. But as we drive the air pressure increases really high. Both needles pointing to 6 o'clock on the gauge. Our truck releases the excess air but it climbs right back up within a second or two. So we are releasing air pretty constantly. When we don't have the trailer attached its fine. When we have a newer trailer it's fine.
We are only going to have this trailer for another hour or so. What is it about the older trailers that might make this happen?? Oh, we have a 2012 cascadia.

 

Sorry about that... The gauge reads about 175. The gauge numbers stop at 150. And no, haven't parked it in a real quite area. But that is definitely something for me to listen for. I'm still new at all this and I know the standard PTI doesn't necessarily cover EVERYTHING that can happen in the road.

Any input is greatly appreciated.

 

Let's say the gauges are a clock face. 150 is at about the 5. The needle is pointing straight down at about the 6. With the way the numbers are spaced on the dial I would say 175 is accurate. The governor does kick on from time to time before that just to maintain a good 110-120. Now it is kicking on and releasing air for Bout 2-3 seconds. Then does it again in about 10-15 seconds later.

 

Never mind. Truck is doing the same without trailer. Shop time for us. Booger!!

 

Yep, that's what I thought. Is this a common enough problem that freightliners and or TAs will have that part handy???