Coolant hoses suck

[papadopalas]

Not that it was hard to disassemble, clean, and put back together. They are sucking shut. I took out the radiator and cooling fan to paint it and figured I'd clean up whatever I could while I was there. Looks real good now.
Here's the way it went. filled the radiator with water and the overflow tank. Ran it till the fan came on and left it alone for a day. (planning on doing a full flush as soon as I get it out in the driveway) Then I read on here about the bleeder bolt and filled it up too and ran it again for the same amount of time.
My son stopped by last night and noticed the three large hoses were compressed. Squoozed together like I'm getting suction somewhere. I opened the radiator lid and they came apart some so I ran it again till the fan came on and turned it off. Everything seemed fine but I didn't watch it for too long (he brought my new grandson over to see me ) This morning they were sucked back together.
Could this be air in the system? Hope I haven't messed something up!!! HELP!!

[papadopalas]

P.S. I didn't check the thermostat while I had it apart. But it seems to be opening a around 195 fine. No overheating issues.

[RRoller123]

Sounds like your radiator cap is bad, it should allow pressure changes to direct flow between the OF bottle and the radiator/block cooling parts of the system.

[SpecialTool]

+1 for rad cap. Mine was rusty inside the metal valve causing it to stick one way and only let pressure out and not back in. Result, collapsed hoses when she cools down.

[TX82FIAT]

+2 check your overflow tank to see if it has risen above the fill line. coolant expands when hot pushing some coolant into overflow tank via a valvbe on the cap. When the car cools the overflow is drawn back into the cooling system via another valve on the cap. Broken valve will create a void as the expanded hot liquid cools and contracts sucking in rubber hoses.