Hi guys,anybody know why my coolant tank with the sightglass would run low but the plastic overflow tank remains full? maybe radiator cap?
When my former 08 Nimbus was doing that, a new radiator cap fixed it. So maybe...
Could be a bad spot in the hose that goes between the 2 tanks.
Mike
Easy to explain:
If there is enough air volume in the cooling system (excluding the overflow tank) it will ABSORB the expansion/contraction of the coolant with temperature change.
Anytime the level in the coolant tank/overflow bottle doesn't move between cold (lower) and hot (higher) YOU NEED TO CHECK COOLANT LEVEL IN THE SYSTEM ITSELF.
Yep, bad cap or hose would explain the full plastic tank. Can you still see coolant in the sightglass?
OR air in closed part of cooling system.
Agree, a broken hose between closed cooling system and overflow would also explain it.
Can't see how a bad cap (won't hold PSI) would do it-- that would likely give MORE movement in the overflow reservoir.
I worked on an 03 u320 a couple of years ago and the hose between the plastic tank and the metal tank was completely plugged and wouldn't let fluid flow between the 2 tanks.
WOW!
So the PSI of the cap (10+PSI) would not overcome the blockage in the hose? Sure sounds like a very neglected cooling system-- but no big surprise.
Yes it was, it had not been serviced in a very long time. Also the air dryer had not been serviced and the air in the wet tank had lots of water in the tank, so that the drain in the bottom of the tank was blocked with sludge.
If the cap is a recovery cap and one of the seals is bad...
Years ago there were some posts about someone using the wrong radiator cap (non-recovery) and running into this issue.
Thanks for the ideas.There is coolant in the sightglass.The cap is old and crusty so will replace.
If the cap is bad, coolant can't be drawn back into the steel tank when it cools down to ambient temperature.
Speaking of pressure coolant tanks, check this out to prevent rust through holes:
Coolant pressure tank rust problem (we all may have) (https://www.foreforums.com/index.php?topic=32277.0)