Coolant overflow bottle not recirculating

[JayRamb]

My coolant overflow bottle isn't functioning like my other two Eagles have and did. My 85 Eagle has a new radiator, water pump, thermostat, and temp gauge is right on the money, no overheating, but I noticed my coolant bottle isn't recirculating as my other's have. I've added a coolant additive in the overflow bottle/recovery, and it hasn't recirculated in the cooling system. My other 2 Eagles did it no problem. The hose from radiator to overflow bottle isn't plugged, the radiator is filled to the top. It puzzles me. Help!

[macdude443]

Make sure the hose is good and tight on the radiator neck and that the hoses has no air leaks. When the car cools and the coolant contracts a vacuum is formed which pulls coolant from the reservoir. When it gets hot the coolant expands and overflows into the reservoir. I had this problem and it was caused by the lack of a hose clamp where the bottles hose connects to the neck.

[macdude443]

You could also have a bad radiator cap.

[JayRamb]

Thanks Mac...I'll check that out and report later!

[carnuck]

Bad cap, pinhole in the system (no vacuum gets made) or bad/wrong cap. This system needs a double seal cap.

[JayRamb]

I noticed that there is an overflow spout on the right hand side of the bottle that goes down from the top of the overflow bottle. Would vacuum be affected by that being open?

[AMCLOVER258]

I had this issue and it ended up being the cap not sealing properly.

[mudkicker715]

I noticed that there is an overflow spout on the right hand side of the bottle that goes down from the top of the overflow bottle. Would vacuum be affected by that being open?

That is supposed to be open.

[eaglefreek]

I noticed that there is an overflow spout on the right hand side of the bottle that goes down from the top of the overflow bottle. Would vacuum be affected by that being open?

That is supposed to be open.

It needs to be open for the system to be able to draw the coolant out of the reservoir.  Make sure you don't have a hole in the overflow hose. Ever try sucking on a straw with a hole in it?

[JayRamb]

I replaced the hose to the bottle today and still nothing. I'll replace the cap that I already replaced this past winter. It's gotta be it. (crossing fingers)

[AMCLOVER258]

What does the the radiator fluid itself look like? could it also maybe be you have WAY excess fluid? (provided the new cap doesn't do the trick)

[vangremlin]

Also, the hose has to fit tightly in in the hole on the top of the bottle so there is a good seal there.  I think from the factory they had a pinch hose clamp on the neck on the bottle to help with that seal.

[carnuck]

I replaced the hose to the bottle today and still nothing. I'll replace the cap that I already replaced this past winter. It's gotta be it. (crossing fingers)

Inspect the cap. It may have a warranty. Is the rad original? If not, I had trouble with the new one in my MJ needing a different cap.

[JayRamb]

Problem solved!!! It is flowin' the way it should be!!! Everyone here had great advice for me with the cap and tube. Thanks!!!

[macdude443]

Good to hear!