Community Forums

dvleemin · 06-01-2014, 05:04 PM

Hi,
I just changed my hot water tank, which has a heat exchanger. In the process, I lost more coolant than I wanted. So I added coolant back into the reservoir, and when I started the engine I got a low coolant warning. I'm wondering if I have some sort of an air lock. Any idea on how to check and/or vent the air. Its for a 05 Itasca Horizon with a Cummins ISL 8.9L.

Thanks,

Darryl

BFlinn181 · 06-01-2014, 05:30 PM

Usually when revving the engine the water pump will push coolant through any air gaps. It will continue to cause the level to drop in the overflow reservoir so you'll have to keep adding coolant until all the air is displaced. Also turn dash heater on full heat to aid in circulation of coolant and removal of air.

edgray · 06-01-2014, 05:30 PM

it is possible that the level in the radiator is too low to create enough suction to draw the fluid from the overflow tank, as intended. The original design was to allow any overflow from a full radiator be captured by the tank, and later drawn back to the radiator as it cools, but you probably already knew that.
Regardless, I suggest you wait till it is cool enough to safely remove the radiator cap and add more coolant there, repeatedly if necessary. Leaving the cap off while running the motor "should " allow any trapped air to burp out the uncapped radiator. Once it seems full, replace the cap and allow the system to become pressurized again. If necessary, you may add more coolant to the overflow tank and then watch it at shutdown to see if the level rises and then retreats upon cooling.

HERE: http://www.irv2.com/forums/f22/how-t...rks-56633.html Is a more professional article on what I said above.

D Lindy · 06-01-2014, 05:31 PM

The coolant level sensor is in the reservoir tank so just keep adding coolant till the level stays constant between the cold and hot marks on the tank. Then run the unit on the road till it reaches operating temps and recheck the reservoir tank level.

wimberleyman · 06-01-2014, 09:13 PM

Darryl,

What kind of chassis do you have? On my Freightliner chassis there is a bleed valve in the line that is used to bleed the air out of the system. It is under the frame on the driver's side back by the engine. You open it and wait until all the air escapes and then close the valve. I did this when I flushed and changed coolant and have had no problems since. Information on how to do this came straight from a tech at FMC Gaffney.

WM

dvleemin · 06-02-2014, 08:14 AM

Quote:

Originally Posted by wimberleyman

Darryl,

What kind of chassis do you have? On my Freightliner chassis there is a bleed valve in the line that is used to bleed the air out of the system. It is under the frame on the driver's side back by the engine. You open it and wait until all the air escapes and then close the valve. I did this when I flushed and changed coolant and have had no problems since. Information on how to do this came straight from a tech at FMC Gaffney.

WM

I have a freightliner chassis. I'll look tonight for that valve - thanks.

dvleemin · 06-02-2014, 08:21 AM

Quote:

Originally Posted by edgray

it is possible that the level in the radiator is too low to create enough suction to draw the fluid from the overflow tank, as intended. The original design was to allow any overflow from a full radiator be captured by the tank, and later drawn back to the radiator as it cools, but you probably already knew that.
Regardless, I suggest you wait till it is cool enough to safely remove the radiator cap and add more coolant there, repeatedly if necessary. Leaving the cap off while running the motor "should " allow any trapped air to burp out the uncapped radiator. Once it seems full, replace the cap and allow the system to become pressurized again. If necessary, you may add more coolant to the overflow tank and then watch it at shutdown to see if the level rises and then retreats upon cooling.

HERE: http://www.irv2.com/forums/f22/how-t...rks-56633.html Is a more professional article on what I said above.

Thanks for posting the link.

I'm not sure that I have a radiator cap though.

See the attached pictures.

BFlinn181 · 06-02-2014, 08:44 AM

Your radiator cap would be on or near the top of your radiator. It serves as a pressure relief valve, you must have one somewhere. If you didn't remove it to fill coolant system back up to full and only added to the overflow tank, that could be why you have air in the system. Find the cap and fill radiator to the top. Put cap on and run engine. Coolant will be drawn from the overflow tank to fill in for air. After letting the engine cool, remove radiator cap and refill.

dvleemin · 06-02-2014, 08:47 AM

Quote:

Originally Posted by BFlinn181

Your radiator cap would be on or near the top of your radiator. It serves as a pressure relief valve, you must have one somewhere. If you didn't remove it to fill coolant system back up to full and only added to the overflow tank, that could be why you have air in the system. Find the cap and fill radiator to the top. Put cap on and run engine. Coolant will be drawn from the overflow tank to fill in for air. After letting the engine cool, remove radiator cap and refill.

I THINK the top of the reservoir is the rad cap - it is a pressure cap - you can see it in the first picture that I posted. The actual rad doesn't appear to have one. Does that make sense?

BFlinn181 · 06-02-2014, 08:58 AM

That could be, I thought the second picture was the same cap from a different angle and that isn't a pressure cap. If it is a pressure cap, it should have a lbs rating printed on it and a spring loaded flange under the cap when you remove it.

dvleemin · 06-02-2014, 09:07 AM

Quote:

Originally Posted by BFlinn181

That could be, I thought the second picture was the same cap from a different angle and that isn't a pressure cap. If it is a pressure cap, it should have a lbs rating printed on it and a spring loaded flange under the cap when you remove it.

It does . . .