Coolant overflow

[porschefan76]

Originally Posted by ike84

Sorry fan, I think I misworded my question (although I appreciate the knowledge on the burp valve too! My new one is coming in the mail so the more I understand about it up front the easier that job will be). You mention the gaskets - are you referring to the two o rings that sit between the valve housing and the tank?

My main intrigue is actually the overflow tube (not valve) which is the open ended tube that comes off the tank (if I remember correctly it's the lowest hose coming off the manifold) and opens to atmosphere. If the system is pressurized then how does this tube not just constantly do gas and coolant? You may have alluded to it acting as a drain for the top of the resivoir tank... Does that mean that it's only purpose is to dump coolant that comes out the burp valve or around the tank cap?

Thanks again for the time (and effort! Love the pics) in helping me!

Sent from my POCOPHONE F1 using Tapatalk

Hey Ike! My bad, sorry yes I misunderstood what you were looking for. When I said gasket, I did mean the o-ring as well. Memory isn't always 100% haha

For the coolant overflow hose, you hit it on the head. It's one job is to allow coolant that gets on top of the reservoir to flow to the outside of the vehicle. Here's another pic I took:


Sorry, it's basic, I didn't want to open Photoshop. But, for orientation, brown arrow is oil fill, orange arrow is coolant fill and florescent yellow is the hole that eventually ends with the coolant overflow tube. It is not under any pressure other than atmospheric unless the cap or valve leak, then it's whatever pressure the rubber seal between the rear trunk lid and reservoir lip can maintain... not much above ambient I'm guessing. If you're familiar with the way the reservoir is connected to the rest of the system, then it is the bottom short hose that goes through the firewall and then it simply routes 90 degrees down near the passenger rear wheel well once it's through the firewall.

No problem on the pictures. Worth a thousand words and all that. Let me know if I left something out. Best of luck!