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In my case, the coolant overflow cap had lost its rubber gasket somehow and no longer fit tightly. Coolant would leak out when going over bumps, and the coolant would then run down the sides of the overflow tank.
Dripping coolant would then be aerosolized by the fan and ended up sprayed everywhere. It dried in a pattern similar to the original poster's photo.
I heated the cap up with a heat gun and re-molded it to fit tightly, as a stop-gap measure while I ordered a new cap. This seemed to work pretty well, but the new cap has now arrived and it fits VERY tightly compared to my old cap.
TLDR: Check the tightness of the overflow tank's cap and the integrity of its gasket.
In my case, the coolant overflow cap had lost its rubber gasket somehow and no longer fit tightly. Coolant would leak out when going over bumps, and the coolant would then run down the sides of the overflow tank.
Dripping coolant would then be aerosolized by the fan and ended up sprayed everywhere. It dried in a pattern similar to the original poster's photo.
I heated the cap up with a heat gun and re-molded it to fit tightly, as a stop-gap measure while I ordered a new cap. This seemed to work pretty well, but the new cap has now arrived and it fits VERY tightly compared to my old cap.
TLDR: Check the tightness of the overflow tank's cap and the integrity of its gasket.
Rex I don’t think the reservoir cap uses a rubber gasket. My ‘06 doesn’t have one. It’s just a snap fit plastic to plastic ordeal.
If yours shows signs of leakage there’s a good chance the 2nd hose, final exit to the atmosphere, is clogged or even the tiny orifice in the cap itself.
Again, just a simple matter of fluid having nowhere to go finding the path of least resistance which is usually caused by the reservoir being incorrectly filled when the car is cold.
Most of these issues can be mitigated not overfilling the reservoir in the first place. It should be approx 1/4 full when cold, this gives expanded fluid from the cooling system somewhere to go 👍
Rex I don’t think the reservoir cap uses a rubber gasket. My ‘06 doesn’t have one. It’s just a snap fit plastic to plastic ordeal.
If yours shows signs of leakage there’s a good chance the 2nd hose, final exit to the atmosphere, is clogged or even the tiny orifice in the cap itself.
Again, just a simple matter of fluid having nowhere to go finding the path of least resistance which is usually caused by the reservoir being incorrectly filled when the car is cold.
Most of these issues can be mitigated not overfilling the reservoir in the first place. It should be approx 1/4 full when cold, this gives expanded fluid from the cooling system somewhere to go 👍
I have a high degree of respect for your posts. You are rarely wrong.
However, this is one of those rare exceptions.
Old cap with missing gasket on left. New cap with intact gasket on the right.
And, with respect, I'm not a believer in the clogged hoses hypothesis.
Ahhhh, I see. When I read your post I envisioned a rubber o-ring. Thanks for clarifying.
That’s why I went to the garage and checked. Actually I believe it’s a variety of factors including old tired hoses and weak clamps. When I looked about an hour ago the hose connecting to the rad cap inlet showed a small amount of pink residue. I grabbed the hose clamp and easily opened it with 2 fingers. Obviously that joint isn’t sealed very tight. Basically everyone thinks the reservoir is somehow cracked when 9/10 times it’s just a hose or clamp issue.
coolant overflow leaking?
