M1089 air leak

[saratoga]

driver side rear front tire deflated and I hear a hiss mixed in the hydraulics. any ideas what this could be?

When i first got it home mechanic mentioned leak around fuse panel on dash. He told me to engage transmission before releasing brakes and I thought this was the issue since i usually forget. He has since transferred and I'm trying to move close to shop to get the crane going. Only was able to get 1 winch

 

[Ronmar]

Well tire deflated could be a bad wheel valve... I dont understand what exactly you mean by “hiss mixed in the hydraulics”...

well that second pic shows an air hose with a fitting just hanging free below the power dist panel. Looks like a line that would run to either the fan control or axle control solenoid valves that are mounted up beside the flasher and appear to be missing on your vehicle, but I may just not be able to see them from the angle the pic was taken at.

 

[Dock Rocker]

If there is a leaking wheel valve and there is water in the tire that may be your “hydraulic “ sound.


Sent from my iPhone using Tapatalk

 

[Ronmar]

Oh, whats the temperature? Could the brakes just be frozen? Ice forming in a wheel valve could also possibly make one leak...

 

[Suprman]

If the ctis tries to do its thing and you have a regular bolt going into the hub where a banjo bolt belongs it can cause a flat tire on that wheel.

 

[saratoga]

the hiss is coming from the area between the rear front tires. theres a pile of hydraulic's mixed in there, thats what i meant.
Ive walked around a few times since the parking and e brake wont build pressure and its the only area that makes an air compressor sound and both rear front tires are low/flat. tried to capture hiss sound in the first posting video

local mechanic is active and took off. worked fine before this
i just figured there was some valve stuck open that i wasnt seeing in tm.

 

[simp5782]

Get your soapy water bottle out and start spraying fittings and lines and see what's leaking. About the best first step for diagnostics on an air leak besides check the obvious that drains are closed fully

Use a remote air compressor to charge the tanks so that the truck isnt running and you can detect the leak better by noise

 

[saratoga]

Use a remote air compressor to charge the tanks so that the truck isnt running and you can detect the leak better by noise

thanks

 

[Coffey1]

That line under dash is air line going to fan or interlock axel and the solenoids look gone to me.

 

[Coffey1]

Tractor protection valve could be leaking it's in that area.
And won't build air well and will dump it quickly if that diaphragm is bad in it.

 

[wheelspinner]

That line under dash is air line going to fan or interlock axel and the solenoids look gone to me.

They are there but I can’t tell if they are connected to the air lines: