Coolant hoses in the engine bay...

[DrWin]

Would anyone chance a guess on what's happening with these smaller hoses that's connected to the steel coolant overflow battle?
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I have a hose coming from the back of the engine somewhere, and a hose comming from the water pump, that meet's up and joins before going into the overflow tank. I also have one comming from the overflow tank, just below the cap, that goes to a plastic bottle.

Is this supposed to be like this? I'm having a hard time figuring this stuff out...
And I dont think it matches up very well with what I find in the workshop manual/tech specifications. :thinkin:

[Ethan Rode]

This is a common modification. The purpose is to insure that any air in the cooling system gets moved to the tank.

[David T]

To properly use the overflow bottle you fill the header tank (the one on the right side) all the way to the top when cold. Now fill the overflow bottle (the one on the left side) to the low (cold) mark. When the car warms up the level in the overflow tank will rise and when motor gets cold it will go down. Always make sure it is always above the low (cold) mark when the motor cools off.

[DrWin]

This is a common modification. The purpose is to insure that any air in the cooling system gets moved to the tank.

...that I won't need this modification if I install the self bleeding kit that DPNW sells?

[DrWin]

To properly use the overflow bottle you fill the header tank (the one on the right side) all the way to the top when cold. Now fill the overflow bottle (the one on the left side) to the low (cold) mark. When the car warms up the level in the overflow tank will rise and when motor gets cold it will go down. Always make sure it is always above the low (cold) mark when the motor cools off.

Lovely to get the actual info on what this is, why it is, and how it is supposed to be used. :)
Would you agree that the self bleeding kit from DPNW does functionally the same thing (getting air out of the cooling system)?

[WHO1DMC]

Lovely to get the actual info on what this is, why it is, and how it is supposed to be used. :)
Would you agree that the self bleeding kit from DPNW does functionally the same thing (getting air out of the cooling system)?

DPNWs self bleeder is exactly the same except for a inline shut off valve. A shut off valve helps if you want to pressurize the system. I have his system.

Dave B.

[Jonathan]

^^ what he said (with pics)

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[Ron]

Lovely to get the actual info on what this is, why it is, and how it is supposed to be used. :)
Would you agree that the self bleeding kit from DPNW does functionally the same thing (getting air out of the cooling system)?With the stock and self bleeder systems, after filling the tank cold, extra coolant will expand and overflow out on the ground as it warms. When it cools, air will be left in the top of the tank for expansion. Normally ~3/4 full. The self bleeder valve should then be shut to prevent masking of problems and the hottest coolant (at thermostat) from being cycled right back into the engine. ( IMO, there is really no need for self bleeders kits since the D comes equipped with an "AIR BLEED CONN HOSE 100502" found in the parts manual. Some online stores label it as a "RESERVOIR HOSE" instead, although it doesn't connect directly to the reservoir....hmmm. If you are impatient or uncomfortable with the process of leaving the cap off while keeping the tank topped off until the air gets out, I guess they are a reasonable option.)
Systems with overflow bottles basically work the same WRT to bleeding, but they have the added function David mentioned. After filling, instead of dumping expanded coolant on the ground, it is retained until it cools and drawn back into the system. They hold a reserve, which means less chances of getting low and need to check as often. A better system.

[DrWin]

Thanks for the input everyone. I get to learn a lot from you guys, I love it.
So it sounds like the selfbleeding kit I got from DPNW is basically a duplicate of what I have already + the valve. :)

The more you know...:thumbup: