My Air compressor governor keeps freezing (3126 setup)

Deville · Jan 25, 2013

All week it's been freezing up. I thought I had a small air leak that was causing condensation, now i'm not so sure. The air system is dry. I've been draining the tanks & i'm not getting any mositure. The air dryer isn't spitting out excess water either.

After the truck warms up it's defrosts & works fine, but i'm impaitent in the cold weather & have been using a heat gun to warm it up.Only takes about 5 minutes.

Anyone have any thoughts about why this is happening & how I can correct it. It's never happened before

guido4475 · Jan 25, 2013

When is the last time the air dryer was serviced? Are you draining all air tanks? My friend was having all kinds of problems last week freezing up and here there was a tank with no drain that was never drained.there is a thing called an automatic moisture ejector that automatically drains tge tanks of any moisture and they are heated as well to prevent freezing.they replace the manual petcock drain cable.i had them on my ford and they were awesome! Not one problem while i had it, and i never had to drain the tanks because they did it for me automatically.

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Deville · Jan 25, 2013

Well to be honest i've never serviced the air dryer. I've been told to just replace it inseatd of folling around with changing the filter. Someone mentioned getting a WEBCO because they have a spin on filter. I drain the tanks on a semi regular basis. I have never had a freezing problem until this week.

Is it common for the governor to freeze up. The heat gun seems to right it fairly quickly. I see that there are adjustments on the Governor itself to adjust the air pressure, maybe I should turn them up?

Slo-Ride · Jan 25, 2013

Good chance your Gov is full of sludge,,Oily and that is what is freezing up on you..
Unless you are bringing your truck inside and outside alot you really shouldnt be building up that much moisture this time of year..Any water in your system is allready froze and will more then likely stay that way untill you hit warmer weather.. Sounds like your Gov is sticking open.
Replace the gov and Ill bet it will clear it up..No big cost at all..easy to do yourself if you can reach it.

Deville · Jan 25, 2013

Slo-Ride said:
Good chance your Gov is full of sludge,,Oily and that is what is freezing up on you..
Unless you are bringing your truck inside and outside alot you really shouldnt be building up that much moisture this time of year..Any water in your system is allready froze and will more then likely stay that way untill you hit warmer weather.. Sounds like your Gov is sticking open.
Replace the gov and Ill bet it will clear it up..No big cost at all..easy to do yourself if you can reach it.

What would cause that problem? Can the compressor itself have an issue as well?

Slo-Ride · Jan 25, 2013

Deville said:
What would cause that problem? Can the compressor itself have an issue as well?

Fairly normal for a gov to get (dirt) carbon, oil in it as the governor itself ages..
For a 20 dollar bill it is a fast fix and a good starting point.
If your concerned your compressor maybe pumping oil you will see it when you drain your tanks and under the air dryer when you sit somewhere for any length of time..A lil oil is common with older equipt..
Dont mess with the settings on the gov unless you have to. Most are preset from the factory to begin with.
Somewhere here in the truck section I posted a few links that has good reading in it concerning Air Systems..Look back a month or so someone else was having trouble. should be easy to spot..

Deville · Jan 25, 2013

ok, i'll look in to swapping the Gov. Despite never servicing the air drier the discharge from it isn't oil or grease. Just normal popping off. I guess I should look in to that also.

Slo-Ride · Jan 25, 2013

Deville said:
ok, i'll look in to swapping the Gov. Despite never servicing the air drier the discharge from it isn't oil or grease. Just normal popping off. I guess I should look in to that also.

Servicing the air dryer is good idea but a little more complex,,If you can change a tire you can do this also in your driveway and save some money.. Just a bigger pain in the butt but very easy to do if you have some tools @ home..

Slo-Ride · Jan 25, 2013

Found those links for ya. The second link has a trouble shooting chart that maybe helpfull.

http://www.bendix.com/media/document...edatasheet.pdf

http://www.bendix.com/media/document...otingguide.pdf

davekc · Jan 25, 2013

If the governor works when it is above freezing, then it could be a couple of things that the cold is effecting. Easy to fix. Get the air down to zero and remove the primary line on the compressor. Pour some air line anti freeze (half pint) in to air line and reattach. Start truck as normal except rev it up some past idle to move it through the system.
You likely have ice in the system. Draining the tanks does nothing if the water in the tank is already frozen. Valves aren't designed to blow ice cubes.

And actually, you don't won't to do that with a frozen system. Drain the tanks when it is warm.
If ice blocks or gets stuck in the valve......guess what?
Anti-freeze (alcohol) in the system will fix it.

Deville · Jan 25, 2013

That's a good link.

Deville · Jan 25, 2013

davekc said:
If the governor works when it is above freezing, then it could be a couple of things that the cold is effecting. Easy to fix. Get the air down to zero and remove the primary line on the compressor. Pour some air line anti freeze (half pint) in to air line and reattach. Start truck as normal except rev it up some past idle to move it through the system.
You likely have ice in the system. Draining the tanks does nothing if the water in the tank is already frozen. Valves aren't designed to blow ice cubes.
And actually, you don't won't to do that with a frozen system. Drain the tanks when it is warm.
If ice blocks or gets stuck in the valve......guess what?
Anti-freeze (alcohol) in the system will fix it.

I've been draining the tanks at the end of the day. bring them down to zero. & leave them empty overnight. I even dumped the suspension & the air ride seats. This is why i'm wondering why it's happening.

I should add that both tanks will build air until 60 pounds than stop building air until the system is thawed out

Slo-Ride · Jan 25, 2013

davekc said:
If the governor works when it is above freezing, then it could be a couple of things that the cold is effecting. Easy to fix. Get the air down to zero and remove the primary line on the compressor. Pour some air line anti freeze (half pint) in to air line and reattach. Start truck as normal except rev it up some past idle to move it through the system.

Dave you know I dont want to go against your Many Many

))years of playing with trucks and dealing with the proplems that can arise,,But...
I have always know it to never pour air line anti-freeze into the system in front of the air dryer..I understand it can cause damage to air dryer canisters..When faced with a total freeze up we have all done it and got away with it. But it is the wrong thing to do..
Think we may have talked about this last year and a Q came up as wheter or not Air line anti-freeze hurts the plastic valves in use today..I do beleive they have come out with something that is safe for plastics??
Besy way to get it into your system is to use the Alcohol Evaporator listed below. Make sure ya mount it down stream of air dryer.
Haldex Midland Alcohol Evaporator A72420 : Amazon.com : Automotive

It would be a cold day in He-- if you freeze up using this product.Well worth the money.

davekc · Jan 25, 2013

That is why only a small amount is needed in a closed system verses unthawing a trailer.
For the times we have done it over the years, never had any issues. If your brakes freeze up and a road service is called, pretty good guess this is what they are going to do unless they tow it to somewhere warm.

Deville · Jan 25, 2013

So why does it build air up 60 pounds than stop??

Slo-Ride · Jan 25, 2013

Deville said:
So why does it build air up 60 pounds than stop??

Not being there I can only guess...
Gov is stuck and thats all its calling for..
Gov is stuck and unloader valve is open/closed..(confused right now which way it works )

davekc · Jan 26, 2013

If it is going to 60 psi and stopping, the place it is frozen is likely behind the compressor.

Deville · Jan 27, 2013

On the top of Governor there is this screw on cap, like a dust cover under neath it there is a nut. What does this nut do?? What's it covering? When I undo it a lot of air comes out of it. Is like a bleeder nut?

guido4475 · Jan 28, 2013

Deville said:
On the top of Governor there is this screw on cap, like a dust cover under neath it there is a nut. What does this nut do?? What's it covering? When I undo it a lot of air comes out of it. Is like a bleeder nut?

Nope, it is an adjustment for the air governor, and youre air pressure. By loosening the nut, and then turning the stud the nut threads on to, You can raise or lower the air pressure limit.They usually are pre-set from the factory.120-130 psi is the norm.They are cheap and easy to replace, under 20 bucks.

BobWolf · Jan 28, 2013

Sounds like the governor on the back of the compressor. 20 - 30 bucks at NAPA or Car Quest
Spend the couple extra bucks for the Halidex or Bendix try to stay away from the knockoff brand. Its a ten minute job
They are a simple animal and the Halidex units can be rebuilt if you can get the correct size O-rings and the bore and cylinder are in good shape so keep the core. Its easier to swap it out especialy on the road. Also when was the last oil change you need good engine lube if you want good air.
In a pinch you can tap and I mean TAP the governor with a hammer handle to get the cylinder to move. if it works its thegovenor.

Bob Wolf