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Hayes air pressure problem

cwk266

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Dec 14, 2016
Messages
46
Location
Fraservalley BC
Hi can anyone point me in the right direction to diagnose a air pressure problem on a Hayes with a cummins compressor?The truck builds pressure to 60-70 psi only.I can hear air being pumped into the tanks till that pressure and then it stops.I am hearing no major air loss with the truck running or when I turn it off.When I pull the button to release the brakes the pressure drops and then builds again to the same pressure and stops.I have attached a pic of the compressor it is setup with the injection pump coming off the back sideIMG_0621[1].JPG
 

lantraxco

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Jan 1, 2009
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7,704
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Elsewhen
Look for your D2 governor, should be connected to the compressor with a small hose, another small hose connected to the air tank senses pressure, most common control:

29-073000_l.jpg


Probably needs replaced if this problem is new and sudden. The adjustment screw is under that black rubber cap.

Typically about $20 at any auto parts store.
 

92U 3406

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Jan 3, 2017
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Western Canuckistan
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Wrench Bender
Gonna go with the governor as well. I don't normally condone throwing parts at stuff but they're usually pretty cheap and the symptoms you describe sound exactly like a governor issue.
 

Birken Vogt

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Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
You could put a gauge on the unloader pressure port to see exactly what is happening. It should have no pressure at first and then when it reaches governor cutout it should suddenly get full tank pressure, with the engine running. This stops the compressor from compressing during that time. Then when you bleed back down to cut-in pressure, unloader pressure should drop to zero and the cycle start again.
 

Midnightmoon

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Nov 9, 2013
Messages
445
Location
Ny
Hard to tell what type of compressor that is. There are two types one has unloaded valve that drains air when compressor builds to 120 compressor never stops compressing govonor bleeds it off. The other type the govonor goes back to compressor and activates a shutoff valve in the compressor. You could temporarily block the govonor line to see if it builds above 110 then shut it down. That will confirm govonor is bad. If your in a cold area ice can cause issues to. If govonor freezes your compressor can overheat and cause ring failure
 

old-iron-habit

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Nov 22, 2012
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Moose Lake, MN
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Retired Cons't. Supt./Hospitals
Last spring we spent 3 days chasing a 70 PSI max air issue in a friends lowboy tractor. Finally, after trying to fill it with a larger remote air compressor, we finally found that the air line to the air horn was leaking where it was routed thru the cab insulation. It was quiet emough, that we could hear it with the truck not running if one one is the cab. Mice had got in and chewed it off. Had to pull interior panels to fix it.
 

Tugger2

Senior Member
Joined
Mar 22, 2018
Messages
1,366
Location
British Columbia
Try it when the wheather warms up,its been cold enough here to cause weird air problems. Might be water in your air tanks,maybe lots if they havent been drained reduces volume. might be a frozen air line. Had the Cummins in my 75ton wouldnt make air ,then it went to making too much like over what the guage showed. I wasnt in a hurry to move so i left it until yesterday things have warmed up and all was fine . Mysterious air problems gone with cold wheather.
You really have to be diligent with draining air tanks and airline antifreeze to keep going when its cold on the coast . Theres a ton ton of moisture in the air.
 

cwk266

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Joined
Dec 14, 2016
Messages
46
Location
Fraservalley BC
thanks for the help.The tapping with the hammer I did before I posted.The top of the compressor you can actually see it in the pic has a tee with smaller lines coming off of it.That tee is coming off a cover which I took off to find a spring diaphram under it.No idea what I was really looking at but the diaphram was not ripped.Those small lines on the top are those lines from the govenor or where on the compressor would the line be that comes from the govenor.Sorry the question is coming from clueless enough not to know where or what govenor is
 

Jonas302

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Jan 4, 2015
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mn
You should be able to follow one of the small lines back to the governor they can be pretty much anywhere
 

cwk266

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Joined
Dec 14, 2016
Messages
46
Location
Fraservalley BC
Thanks will be at truck later today with the info provided here I should be able to figure it out thanks from a backyard mechanic that dont know shxx
 

cwk266

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Joined
Dec 14, 2016
Messages
46
Location
Fraservalley BC
I figured out why I could not find the governor there is none connected to the compressor.I found it bolted to fender with no lines to it.The very top of the compressor there is a tee with small lines.One goes over to the upper rad hose housing to something mounted to it and exits to the control for the shutters in front of the rad(see pic)The other small line goes to the firewall to a fitting that exits as a larger line that goes under the truck to (see pic)to this unit mounted on the frame rail.If there was a govenor is the line connecting it to the compressor at the top of the compressor where the tee is on the pics.Not sure if I am doing a good job on asking my question.There is no govenor hooked to my compressor I understand that there should be and the system probably was butchered but it was working somehow just like this.The pressure would build to 120 I could swing the dead man arm up and it would stay up and I cant really say I recall hearing the compressor unloading but it must have because nothing has been blown apart?IMG_0628[1].JPG IMG_0629[1].JPG IMG_0630[1].JPG
 

DMiller

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Hermann, Missouri
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You now have a fabricobbled mess
How long have you had the wagon? Has it always been this way?
The ‘T’ is obviously new so some rerouting has already occurred.

the line leading to the engine is attached to a Fan/shutterstat
Appears the other side feeds off of a brake valve supply pressure side so as pressure slowly comes up it reaches equilibrium of unloader spring pressure and air tank supply pressure

the line coming up from the air valve needs to go to RES Reservoir on the D2
The line to the shutterstat off that same side of the D2
A single line from Unl unload to the compressor head and the E exhaust left open
Will be 3 Res ports plug the final one, will be 3 Unl ports plug two unless have a air drier then one line will need to run to that device from Unl
 

cwk266

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Joined
Dec 14, 2016
Messages
46
Location
Fraservalley BC
thanks Dmiller I like your term fabricobbled.I was torn between calling it butchered or genius solution by someone that refuses to to buckle under there is always a way if the will is present.I dont know which it was the truck came to me like that but I am guilty of both LOL Thanks for the clear instructions on putting back to the way it is supposed to be.I am not going to waste time plumbing in the governor that was bolted to the fender but not hooked up.I will assume its hooped pick up a new one and follow your directions.Once again heavy equipment forum to the rescue.Thanks to all that posted
 

DMiller

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As a side note, the Brass 90 in front of the shutterstat, is capped, look at the top radiator tank, if there is a similarly capped fitting or a pipe plugged port there install a new line between the two, that is the T-stat housing bleed vent. And replace that shredding Shutterstat line.
 

cwk266

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Joined
Dec 14, 2016
Messages
46
Location
Fraservalley BC
Thanks DMiller picked up a new govenor followed your instructions and its back to business.Without your help this would have been a mobile mechanic service call I would have never figured this puzzle out on my own no matter how long I would have looked at it like I knew what I was looking at and looking for.The fabricobbled job was useable to some time the truck drove off the lowbed when it got here and probably a dozen times over several years using that built to haul stumps and brush box here at home
 
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