Anti-freeze out of Air Box Drain Can

[GnarlyBus]

After driving the bus for about 30 miles (we movie ever few weeks) I woke up go find antifreeze dripping out of the air box catch can on my 6v92. A good amount of coolant came out. When I recently changed the oil, I drained this can and didn't have any water in it.

After some research it sounds like a cylinder liner could be leaking...

Where do I begin?

[luvrbus]

Pull the air box covers if one is leaking it will show on the outside of the liner if the head or gasket is bad it will leak on the inside of the liner, adding a couple of pounds of air to the system helps a bunch when looking for a leak on a 92 series, do that first some times it is a simple 0-ring leaking on the after cooler or a leaking after cooler 

[GnarlyBus]

I had to add oil to the engine to get the level up to check for milky oil. When I did, the antifreeze started dropping out of the catch can again. Curious, I opened the catch can up some more and then it was really flowing out pure coolant.

So far the oil looks clean and not milky but it's been sitting for two days.

I'll pull the air box drains and report back. Thx.

[luvrbus]

A injector tube will leak to inside of the liner too

[eagle19952]

I had to add oil to the engine to get the level up to check for milky oil. When I did, the antifreeze started dropping out of the catch can again. Curious, I opened the catch can up some more and then it was really flowing out pure coolant.

So far the oil looks clean and not milky but it's been sitting for two days.

I'll pull the air box drains and report back. Thx.

if the crank journals have run with coolant/oil you could have a whole different can of worms....

[GnarlyBus]

Opened up the passenger side...what am I looking for exactly? Rotate the engine and watch these holes?

[luvrbus]

Add a little air pressure to the system no more than 5 lbs if the liner o-ring are bad it will leak check both sides it will puddle at the bottom if one is leaking 

[GnarlyBus]

if the crank journals have run with coolant/oil you could have a whole different can of worms....

Not seeing any coolant in the oil intern dipstick or other places yet. So hopefully that hasn't happened.

[GnarlyBus]

Add a little air pressure to the system no more than 5 lbs if the liner o-ring are bad it will leak check both sides it will puddle at the bottom if one is leaking 

Not sure how to do this. What system do I add the pressure to and where do I tie in at? I do have a mityvac hand pump, maybe I can use that?

I appreciate the help!

[luvrbus]

You can remove a plug or a gauge sender on T stat housing to pressurize the system

[buswarrior]

A little pressure to the coolant system, mimicing the operating pressure, so that any leaks will expose themselves.

Lots of leaks won't leak unless there is a little pish behind them.

A jig to fasten in somewhere with a shraeder valve, like your tires, and emphasis on A LITTLE PRESSURE...

Happy coaching!
Buswarrior

[GnarlyBus]

I setup a ball valve to add pressure to the system with a mityvac hand pump. It does build pressure but I can't get it up to 5 psi. After pumping, I noticed the coolant dripping out ABOVE the air holes (the coolant doesn't appear to be inside the cylinder at all, but outside) on the middle cylinder liner on the left side. Again, the bus isn't perfectly level and the left side is lower.

I've attached a video of the leak.

https://www.youtube.com/watch?v=5QK6j-w1rFo

[Scott & Heather]

That's a great video. Free bump to the top for someone to view that leak on his video and chime in.


Sent from my iPhone using Tapatalk Pro

[chessie4905]

Turn engine slightly for piston to uncover ports in that cylinder and repeat.
So when did you get it hot/ overheat in past?

[luvrbus]

It is the liner seals leaking you have 2 o=rings seals above the ports on the liner in the block, that is a bummer the heads and pan need to come off and pull the liners to replace 30 bucks of o-rings, thanks for the video