relay valve still leaking air??

What did you figure out I’m having a similar situation

 

I have a 2014 Pete. I was loosing air from the valve relay exhaust port when my hand valve was pushed. When I pushed my brake it would stop. When my hand valve was pulled and I pushed the brake air would come out the park brake exhaust on the firewall. I replaced the valve relay and I still had the same issue. I checked all the brake chambers and non were bleeding back or leaking. I finally found out there is a quick release valve mounted on the frame above the front drive axle. It was the culprit. $52 replacement fixed my problem. I hope this might help someone else

 

Yes it’s going to be a qr-1c valve. If you are leaking air from relay valve exhaust. Remove the airline on top of qr-1c valve (balance port) going to relay valve and release parking brakes. If the air is leaking from top of qr-1c from balance port it’s your qr-1c valve. Use wheel chocks when testing the valve

 

I have a 2010 kenworth doing the same thing did you ever find out what it was