Good day everyone. I recently purchased a 2005 XC90 T6, about two months ago. Out of nowhere the low level sensor came on for the coolant. Upon checking the coolant bottle it was in fact low. So I filled it up, and did so for a week or so. I did some searching on here and other sites, and the consensus was to check and inspect the hoses and bottle. Sure enough the bottle had a number of small cracks in it. So replaced the bottle and cap. The system seems to be preforming better than before the replacement. However, I still have a leak somewhere or need to do something else... Can anyone tell me if there's a way to pressurize or depressurize the system?!?

I will fill the bottle, once running the light comes on and upon inspection the level is in fact low. Once cool enough to fill I remove the cap and the system depressurizes, and the level raises to almost max. I top off a bit and repeat.

Please advise!!! Is there a way to remove the excess air in the system, or do I need to "bleed" the system? I'm not sure what to do?!?! Or am I off to the dealer?

 

this link seems promising.
Coolant Flush How-to: Volvo XC90 (2003-2014) - 2008 Volvo XC90 3.2 3.2L 6 Cyl.

 

I had a warning light come on coolant was not in the resiviour added some and the warning light went out taking it in to see if theres a leak its a 2005 xc90

 

There should only be pressure in the coolant system if the car is still warm because of the expanded coolant. Never open it while its hot for obvious reasons and keeping your skin on your hands. If you have no visible leaking and pressure when its cold it is pressurizing from the engine and you have a coolant leak in the motor.

 

so I had a pressure test and he said he could see the coolant coming out of the unit that holds the coolant could see it burning off when it hit, so we replaced that bottle. I am going to have to keep and eye on it now and see how it goes

 

We went to the mountains and on that trip the coolant level warning went off. I cracked the cap a little bit and the pressure filled the level back up to turn off the warning since it was hot. I stopped at the auto parts store and got more coolant just in case. When we got back home I let the car cool off and refilled the coolant back up to normal.

About a week later I noticed the carpet on the floor getting dirty for no reason. When I touched it, it was wet. After looking into it, the heater radiator was leaking from the side very slowly drip by drip.

I replaced the heater radiator and it stopped loosing coolant and wetting the floor.

Problem solved.