Problem with Air - Steel Soldiers::Military Vehicles Supersite

CARNAC · 07-29-2009, 10:10

Been having problems with my air system.

It appears I am building air and the safety valve is cutting loose more regularly than in the past that I can remember. My guage is reading 0 but the tanks are full of air. I have no air to the windshield wipers which if I remember correctly go directly from the compressor.

I have the air assisted power steering. Thinking that was leaking, I turned off the valve to that.

I checked the trouble shooting TM but see nothing there reference the safety valve releasing excess pressure yet the guage reading zero and the wipers not working.

Ideas???

gimpyrobb · 07-29-2009, 10:16

Sounds like seperate issues. The saftey valve has to vent the system, or is it the air govner kicking out?

cranetruck · 07-29-2009, 11:17

Do you have air in both tanks or just the "dry" one? The deep fording kit includes a check valve between the tanks...

shepsjeep · 07-29-2009, 22:00

I agree with Gimpyrobb about the safety valve. The Air gov was leaking on both of my trucks. Take a spray bottle of soapy water and start spraying the lines and components, it will raise it's ugly face.

Rick

CARNAC · 07-29-2009, 23:07

Update,

I have compressed air that I would definately suspect is 120 psi or greater in the air tanks.

I do not have compressed air to the horn, guage, or wipers. I disconnected the air line back to the compressor itself and still have no air coming out at the top of the compressor. The side air line that feeds the breaks was not tested but must be working since I have brakes and the air tank safety valve is cutting loose to relieve that pressure.

Bad compressor since it ain't feeding the top line?

gimpyrobb · 07-29-2009, 23:19

Did you check for a plugged up line? I thought that top line is how the compressor is governed by the air gov on the firewall. The side output is what heads to the tanks. You got air blowing out both tanks? I have a new air gov if the boys thinks that might be bad. I'm not sure. I think the gov not working would cause your over pressure problem making the saftey valve have to vent the pressure. Anyone else?

m16ty · 07-29-2009, 23:22

I'd say the compressor is working fine if you've got pressure in the tanks. This is very odd

. All of the air powered accessories pull right off the tanks. I'm going to say you have a plugged line somewhere. I'd start tracing the lines from the tanks and breaking them to see where the pressure stops.

Speddmon · 07-30-2009, 00:44

I have to agree with m16ty, if the compressor were bad, how did you get the air in the first place?

shepsjeep · 07-31-2009, 00:44

It sounds like the compressor is working fine, passing air to the brakes through the air Hyd. Cyl. I agree with Gimpy on this one. The Air gov is the first place to check, then clogged lines. It looks to be the only thing in common with your failures. I think we all would be curious as to what the final issue is on this one!! Please post when you find out what it is.

Thanks,
Rick

Jake0147 · 08-02-2009, 11:04

The little line at the compressor to the governor on the firewall is not from the compressor, rather TO the compressor. It's the signal line that cycles the compressor on and off to match the demand. Disregard that for this diagnosis.

The symptoms you describe do have a commonality. Follow the line that goes from the governor, to a bulkhead fitting on the firewall, continues on towards the driver's side, down the firewall, and back along the frame. ALL of the missing items get air from that line, including the governor. If that line does not receive system pressure from a stoppage (external or internal causes...) then you will first loose the function of all the items mentioned, and second, the air governor will not sense "true" system pressure and therefore will never cycle the compressor off, thereby not limiting the pressure to the rest of the air system that still does have air, at which point the failsafe mechanism kicks in, that being the pressure relief valve on the air tank...

I'd be lying if I tried to guess where in that line the problem might lie, except that it would have to be BEFORE that bulkhead fitting beside the air governor, so start there and work downwards and back, and if there's no external damage or kinking, then I'd expect low spots could accumulate more crud, and the fitting ID tend to be smaller than the line ID by just a touch in general (there are exceptions) so those might be a likely candidate.

Or maybe it's a bad phlegm baffle on the muffler bearing and I'm just smoking opium, but that's where I'd start.