04 International 9400i Secondary Tank Losing Air

check engine air valves... for example bad VGT valve may sloooowly leak air with minimal sound

check trailer control valve, front relay valve.. they have sound mufflers on exaust ports so u cant hear leak sound

 

My '02 9400 had this problem also. Turn out to be a leak on the quick connect fittings on the lines from the governor. Only one was leaking, but replaced them both with compression fittings. Problem solved. By the way I got the tip from someone here on this forum.

 

I found my air leak going to secondary. It is a black with blue tracer pex style hose. It is either disconnected or broken above the brake chamber. Problem i am having is??? Does it plug into something or do i need to look for a broken line further back? If its broken it is an awful clean break.

 

Probably popped out of a quick connect fitting.

 

i was thinking purge valve..but since they replaced the dryer (which comes with new purge)..then maybe not.

i replaced my governer dryer and leader hose after changing my air compressor ( was blowing oil in my system). my new setup pops off every few minutes while idle..and even quicker while on the road. i just got used to it.

im guessing ur just gonna have to soap and water every air line and fitting u see!

 

I have been under and over the truck. Cannot find any detached or free quick connects. Looking for a good air hose diagram. If you know where i can locate any help would be appreciated.

 

International doesn't publish any air diagrams like they do with wiring. Google search of bendix air diagrams for a general schematic.

 

this seems useful..

HNC Medium And Heavy Duty Truck Parts Online | Bendix Air Brake Diagram

 

Yep, that's the one!