Dash brake valve leaking when foot brake is pressed

[Redland1]

Recently my dash brake valve started leaking from the yellow knob when I press the foot pedal and it leaks briefly then stops and also leaks sometimes with just the yellow knob pressed in. When I pull the trolley bar it leaks from the red knob. I’d also like to mention that yesterday morning when I started my truck it would not build air and I went looking for a leak and found it coming out of the exhaust port on the brake manifold that’s on the firewall. The only way I got it to air up was by holding the red and the yellow knobs. in and then it started to build pressure. So far I’ve put a vice grip on each brake chamber service line and then checked the knobs to see if they are still leaking and they were.
(2003 international 9900i,04’ ISX 870)