Air brake system help

[oifla]

Hello all,

I'm sorting through some issues with my International 8100. When I first got the truck, it would take forever to build air pressure (like 20+ minutes). I located a faulty gasket/seal atop of the air compressor. I replaced that, build pressure normally now.

Now that the compressor isn't leaking, it builds too much pressure. Goes way past 150 psi, so much so that it blew a line on one of the tanks yesterday after a drive.

The setup on this truck is not one I'm familiar with. It doesn't have an air dryer and I'm not sure how it is all supposed to work but I'm guessing something is wrong (high PSI readings and the blown line, etc.).

It does have a bottle with an anti-freeze solution in front of the compressor: https://photos.app.goo.gl/o7SwXRPuLtPxsyDQA

I'm not sure what else is on the compressor itself but here's another pic of the back of the unit: https://photos.app.goo.gl/ZeAX51pdkrurFx1LA

The tank setup is a little confusing to me. There are two tanks and they don't seem to be connected (they can be emptied individually via manual valves on the sides). Only one tank seems to have a pressure relief valve (labeled B in this pic) and it also has a manual drain that seems to collect a ton of wet gunk (labeled A in the pic): https://photos.app.goo.gl/qAYnHvrsirdaLtg5A

Both A and B can be better seen here: https://photos.app.goo.gl/L3BFAxDQ5dYFdgHA8

The pressure relief valve seems to not be working correctly so I'm getting a new one.

The back tank doesn't have any pressure relief as far as I can tell (hence the blown air line). There is a quick connect for an air hose (labeled C on the following pic: https://photos.app.goo.gl/Fp2LeZTBEJM5jE2eA). I'm not sure if that's where the pressure relief valve goes on that tank and someone thought it would be handy to have a quick connect or what is going on with this.

What I labeled as D is another mystery item. It it attached to the first tank and looks like some sort of pressure relief but it is covered with a rubber cap. I'll get a pic of the 'valve' next time. No clue what its for.

Anyhow, that's a lot of info (sorry!). Advice from anyone who knows how these systems are supposed to work would be greatly appreciated as I am at a loss right now. I can take more pics if it helps, let me know what you'd like to see if I missed anything. Any help would be super appreciated. Thanks!

A.

 

[Tyler d4c]

Sounds like you have a bad governor to me personally I'd be installing a dryer also

 

[Tinkerer]

The quick connect coupler is not unusual in an air brake system.
It is very handy to inflate tires.
Or charge a brake system on another vehicle for some reason.
Rubber caps on some styes of pressure relief valves is not unusual.

 

[mekanik]

Item D is a quick coupler that is used to charge the air system.
It looks like you were very generous with the silicone when you repaired the leaking gasket
on the compressor. You may have blocked the unloader with silicone. There is an unloader
kit that you can install in the compressor. That might be a good place to start after you verify
the governor is working. Does the low air pressure light and alarm work? Light and alarm goes
off/on at around 75 psi. The governor is bolted to rear of the compressor head with two 5/16" bolts.
When the air pressure reaches 120psi it sends pressure into the compressor to open the intake
valves so the compressor stops pumping. A new governor is not expensive it might be worthwhile
to replace it and see if it solves the problem. You could also take the plug out of the governor
between the two 5/16" bolts and plumb a pressure gauge in. When the air pressure reaches 120ish
psi the governor should open and the gauge you plumbed in should read reservoir pressure.

 

[Vetech63]

It does have a bottle with an anti-freeze solution in front of the compressor: https://photos.app.goo.gl/o7SwXRPuLtPxsyDQA

That is a bottle for a suction draw air line antifreeze set up. I thought they put alcohol in those.

The tank setup is a little confusing to me. There are two tanks and they don't seem to be connected (they can be emptied individually via manual valves on the sides). Only one tank seems to have a pressure relief valve (labeled B in this pic) and it also has a manual drain that seems to collect a ton of wet gunk (labeled A in the pic): https://photos.app.goo.gl/qAYnHvrsirdaLtg5A

The first/primary tank is what they call the wet tank. It will collect the most water as he compression of the air mixed with humidity can create a lot of it. The secondary tank is usually the tank that feeds the air system

Both A and B can be better seen here: https://photos.app.goo.gl/L3BFAxDQ5dYFdgHA8

These are use to put air in tires or blow filters out.

The governors are cheap, replace yours. They are preset for the load and unload pressures but be sure you plug the correct holes. They can be mounted in multiple ways hence all the threaded positions. I would definitely
replace the blown down valve if you blew a line out. I believe they are set to blow off at 150 psi if I remember correctly.

What I labeled as D is another mystery item. It it attached to the first tank and looks like some sort of pressure relief but it is covered with a rubber cap. I'll get a pic of the 'valve' next time. No clue what its for.

A pic of this would help






.

 

[oifla]

Item D is a quick coupler that is used to charge the air system.
It looks like you were very generous with the silicone when you repaired the leaking gasket
on the compressor. You may have blocked the unloader with silicone.

Yes, i think you are correct. I'm waiting on the replacement pressure relief valve but I think the extra silicone was causing the problem.

Thanks

a.

 

[Truck Shop]

The best thing you can do is remove and toss that alcohol injection bottle. All that does is dry out
the valves in the air system.

 

[oifla]

The best thing you can do is remove and toss that alcohol injection bottle. All that does is dry out
the valves in the air system.

Yes, i plan on doing that before next winter. Get rid of the bottle and set up a proper dryer.

a.

 

[oifla]

Yes, i think you are correct. I'm waiting on the replacement pressure relief valve but I think the extra silicone was causing the problem.

Thanks

a.

I'm confirming that the problem was the extra silicone blocking the unloader valves. I'm still not super clear on how it is the unloader valve works but I scraped off the silicone and replaced it with the gasket set (which I should have done in the first place! thanks NAPA for never having anything in stock LOL), works perfectly now.

thanks all!

a.