is it me, or is this thing useless??
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
is it me, or is this thing useless??
So for the cars that have a header tank and overflow tank for the cooling system.... what purpose does the overflow bottle serve besides just being a catch can? On most cars coolant will move in and out of the tank as the engine heats and cools. When it gets low you service that and not the radiator directly. The overflow tank in my car is nothing but a storage location for old antifreeze. If my coolant gets low it is low in the header tank and I have to service it there.
Do I need to bleed the air from the overflow hose? How silly would that be?
I'm done now.
Matt
Do I need to bleed the air from the overflow hose? How silly would that be?
I'm done now.
Matt
Melting Slicks
Joined: Jan 2009
Posts: 3,181
Likes: 286
From: Puyallup Washington
A couple of things will keep coolant from moving between the radiator and the tank. One is a bad radiator cap as the system pulls coolant into the radiator with vacuum created by the coolant in the system cooling and contracting. Another could be a blockage in the recovery tank that keeps coolant from moving. This was the case with my 1992. The recovery tank was blocked with rusty sediment down at the bottom of the inlet into the tank. Nice green antifreeze in the recovery tank, rusty red water in the cooling system.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
ANother issue can be with the upper reservoir, you called the header tank. It will bleed the pressurized system and the coolant cannot be drawn back up from the overflow tank. I have replaced both of my upper reservoirs. One was a visible leak, the other did not show a sign of leaking, but as soon as I changed it, system was back to proper operation. 
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
A couple of things will keep coolant from moving between the radiator and the tank. One is a bad radiator cap as the system pulls coolant into the radiator with vacuum created by the coolant in the system cooling and contracting. Another could be a blockage in the recovery tank that keeps coolant from moving. This was the case with my 1992. The recovery tank was blocked with rusty sediment down at the bottom of the inlet into the tank. Nice green antifreeze in the recovery tank, rusty red water in the cooling system.
The cap is good to go.
Matt
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
You are definitely losing that vacuum. You are supposed to inspect/replace the radiator cap every time you get an oil change. That's a little much, but since you can get a new cap for about 15 bucks at the auto store, I would just get one. While you are there, get some vacuum line that will fit over and seal with the 2 drain nozzles that allow the flow of coolant in and out of the reservoir tank. Blow just to see if they are clogged. With all the junk that that tank can fill up with, you never know.
Another thing to check would be the cap for the reservoir tank. I'm pretty sure it won't cause you problem, but it's a good thing to check. It was designed very well and GM has discontinued it. It might be worth a replacing as well.
Another thing to check would be the cap for the reservoir tank. I'm pretty sure it won't cause you problem, but it's a good thing to check. It was designed very well and GM has discontinued it. It might be worth a replacing as well.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
You are definitely losing that vacuum. You are supposed to inspect/replace the radiator cap every time you get an oil change. That's a little much, but since you can get a new cap for about 15 bucks at the auto store, I would just get one. While you are there, get some vacuum line that will fit over and seal with the 2 drain nozzles that allow the flow of coolant in and out of the reservoir tank. Blow just to see if they are clogged. With all the junk that that tank can fill up with, you never know.
Another thing to check would be the cap for the reservoir tank. I'm pretty sure it won't cause you problem, but it's a good thing to check. It was designed very well and GM has discontinued it. It might be worth a replacing as well.
Another thing to check would be the cap for the reservoir tank. I'm pretty sure it won't cause you problem, but it's a good thing to check. It was designed very well and GM has discontinued it. It might be worth a replacing as well.
I can't see how the cap on the overflow tank relevant.
Matt
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
So.... what I am hearing is that the coolant should be migrating between the two tanks like I thought. I must have a clog in the line of something like that.
Thanks everyone!
Matt
Thanks everyone!
Matt
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Safety Car
Joined: Dec 2008
Posts: 3,588
Likes: 10
From: North New Jersey
Hmmm... My reservoir tank never gets used either... So you guys are saying that the tank should fill with antifreeze and then empty? Mine is basically dry all the time but I dont have any cooling problems...