Hi again everyone. My Disco is not my BFF this week. So, I ordered a new expansion tank cap just a preventative maintenance since the o-rings on the old one looked pretty flat. I installed the new one today and it looks like the overflow tube has been doing it's job. There is coolant all over underneath the area where that hose points. I haven't actively seen it happen, but I guess it's possible it's also leaking from around the new cap. I'll inspect further with it running hot, but wanted to see if it's possible that the old cap wasn't holding enough pressure to overflow or if the new cap sux. Thanks for any input .

 

Problem solved. I ran the truck in the garage for a few minutes and sure enough saw coolant drip out of the overflow tube. I took the cap off and noticed that it didn't hiss and was all wet up past the o-rings where the old cap looked dusty and dry. It's a Motorad item so I'm guessing it's on par with the thermostats in quality. I'll be returning it.

 

yeah I had the same problem with a new defective cap once. Coolant would spray from the overflow tube. Bought another one from a different vendor and worked fine.