Secondary air tank issues

I’m having a weird issue with my truck and this last round was the worst ever. Basically the secondary tank will only fill to 105 psi. Sometimes it will go to 120 but it’s rare. Normal operation is 120. Now when I am at a stop light holding my foot on the brake my air depletes pretty fast and it starts with the secondary first. If I hold my position at the stop like with my trolley lever I don’t lose air, At all. Now cannot hear this leak and have good hearing. I have had the truck off etc and nothing. I’m suspecting it’s an air can on the truck that I have had issue with that brake specifically but it doesn’t make sense because I cannot hear anything

The only thing different is I bought a newer 2015 reefer. Only other problem With the trailer is jacks for when you have the supply knob out don’t connect to the trailer so I’m suspecting a ride height issue with the trailer but I don’t think that’s has a play in this issue.

Thanks.

 

I have done that sadly. Im going to go inspect it a bit closer in the am. Thanks the recommendation, definitely gonna do it again tho and will let you know. Still guessing an air can but I just had this truck inspected so I’m kinda surprised and that why I half wondered if it was the trailer as that’s the only thing “new”

 

Thanks for all the reply’s. I put it in the shop today as the local weather here has been garbage. They found a front brake diaphragm with a hole in it. That solved the foot on the brake and loosing air situation. Oddly enough it never made noise for us. I picked it up thinking that was it but it’s not. I’m still losing air out of the secondary circuit tank while not using anything. And that’s not hooked to a trailer. I bobtailed it to the shop. Hopefully the weather will break and I can get a much better idea to what is going on.

 

Yes it does. It’s the truck for sure. Now with the air diaphragm that had a hole in it is replaced we shall take a look tomorrow see why the secondary tank keeps dropping off. Thank you!