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Coolant Reservoir. Lets find an alternative
Posted: Fri Jan 09, 2004 1:55 am
by ciper
It seems that the coolant reservoir would be simple unit.
I have a spair one at home but if I remember right it has 4 holes.
Two open
One has a one way valve?
One as a pressure release
Is the one opening really a one way valve? Does someone have a broken unit they can open up?
Seems we could find a tank with two holes and a coolant cap then T two of the lines together and use an external one way valve.
Did the JC replacement tank have the valve?
Posted: Fri Jan 09, 2004 2:39 am
by vrg3
I presume the reason you want an alternative is that it's dumb to use a plastic piece? If that is the case, why not just adapt a new WRX tank?
Anyway, let me write here all I know about the tank:
It has a holder-thingie for a radiator cap, and 4 nipples:
One small one coming right off where the cap attaches.
One small one coming off the upper passenger side on the back.
One large one coming off the back near the top.
One large one coming off the back near the bottom.
The small nipple coming right off the cap is just like the nipple coming off near any radiator's cap. It goes to the overflow bottle. Whether or not it is connected to the bottle depends on whether the radiator cap is open or closed (which depends on system pressure).
The small nipple on the back goes to the "burp screw" portion of the radiator. There is a check valve built into this nipple allowing coolant (and, more importantly, air) into the bottle but not allowing anything back out (since you don't want to pump water back into the radiator).
The upper large nipple goes to the upper coolant fitting on the turbo. When the engine is running, this is how the tank supplies the turbo with coolant. When the engine is off but the turbo is still cooling down, vaporized coolant travels from the turbo to the tank this way.
The lower large nipple goes to a nipple on the water pump, next to the nipple that goes to the heater core. When the engine is running, the water pump supplies coolant to the turbo through this hose.
I believe that aside from the aforementioned check valve, the bottle is all one chamber. The volume of this chamber is about 0.4 liters.
The lower coolant fitting on the turbo connects to the passenger side cylinder head. When the engine's running, this is where the coolant goes after passing through the turbo's water jacket. When the engine's off and the turbo's cooling down, coolant gets sucked into the turbo from the head.
Posted: Fri Jan 09, 2004 2:44 am
by ciper
Does anyone have an image of the WRX tank outside of the vehicle, or perhaps an image from the service manual.
Posted: Fri Jan 09, 2004 2:50 am
by vrg3
I sold one to subiekid; maybe we can get him to take a few pictures. I'll email him.
Posted: Fri Jan 09, 2004 3:38 am
by legacy92ej22t
ciper wrote:Does anyone have an image of the WRX tank outside of the vehicle, or perhaps an image from the service manual.
I can try to hook up with my this buddy this weekend that has a wrx and take a pic of his. It's in the car though. Let me know if I should bother

Posted: Fri Jan 09, 2004 4:29 am
by ciper
I found that 02 and early 03 WRX have one radiator cap while late 03 and one have two. Also late 03 and on have +15 wheel horsepower

Posted: Fri Jan 09, 2004 4:54 am
by vrg3
Yeah... I guess the extra cap was to allow for quicker burping or something?
http://www.graphics.cornell.edu/~v/pics ... ne_bay.jpg
(That's an '04 STi but the cooling setup is the same as 2-cap WRXes)
Hey, Art, tell us -- is there just a tee between the overflow hoses from both caps that let them both go to the overflow bottle?
Posted: Fri Jan 09, 2004 5:15 am
by ciper
YIKES! Watch out for painted WRX tanks. The paint comes off inside the cooling system and has damaged a couple cars. Here is one of the threads I found
http://forums.nasioc.com/forums/showthr ... did=404611
Ive heard of a partially clogged radiator from this too. Sucks!
From that thread we find
21132AA075 Tank Assy Water
$76.91 from subaruparts.com
Who has done the WRX conversion? We need a write up.
Posted: Fri Jan 09, 2004 6:10 am
by vrg3
Yes, I believe they've stopped painting them now. The one subiekid has isn't painted.
Posted: Fri Jan 09, 2004 7:00 am
by subiekid
as requested by the great vgr3........
if you need any more i can take them.
Posted: Fri Jan 09, 2004 7:11 am
by vrg3
Thanks, dude.
Mmmm... Jelly Belly.
Posted: Fri Jan 09, 2004 7:19 am
by subiekid
you know it. they are the best.
Posted: Fri Jan 09, 2004 8:44 pm
by ciper
Which of the tubes has the one way valve?
Posted: Fri Jan 09, 2004 8:59 pm
by vrg3
On the WRX tank? The small one on the top, I believe. subiekid can verify that.
Look in the STi engine bay picture to see how the tank is mounted.
The big nipple going towards the turbo goes... to the turbo.
The small nipple coming right off the radiator cap goes to the overflow bottle.
The other small nipple goes to the radiator burp nipple.
The big nipple on the bottom goes to the water pump.
Posted: Fri Jan 09, 2004 9:05 pm
by teaguespeed
subiekid wrote:you know it. they are the best.
jucy pear flavor jelly belly is the best candy ever made.
Posted: Fri Jan 09, 2004 10:52 pm
by mTk
teaguespeed wrote:subiekid wrote:you know it. they are the best.
jucy pear flavor jelly belly is the best candy ever made.
HELL yes it is!!!!
MK
Posted: Mon Sep 19, 2005 6:51 pm
by andys2
*The upper large nipple goes to the upper coolant fitting on the turbo. When the engine is running, this is how the tank supplies the turbo with coolant. When the engine is off but the turbo is still cooling down, vaporized coolant travels from the turbo to the tank this way*
I think coolant comes from the turbo into this port.
*The lower large nipple goes to a nipple on the water pump, next to the nipple that goes to the heater core. When the engine is running, the water pump supplies coolant to the turbo through this hose.*
I think water goes back to the pump via this port.
*The lower coolant fitting on the turbo connects to the passenger side cylinder head. When the engine's running, this is where the coolant goes after passing through the turbo's water jacket*
I think this is the turbo supply port.
But I could be wrong........
Posted: Mon Sep 19, 2005 8:31 pm
by vrg3
Hm, yeah, actually, I think you're right. I guess for some reason I was thinking the water pump pumped the other way.

Posted: Mon Sep 19, 2005 9:12 pm
by snowboarded
I had one of these installed on my car for a few hours, then I went back to the stock legacy- moded one, I plan to put another one in tho. Big Thanks to Matt(Phatty) and V.

Posted: Mon Sep 19, 2005 10:04 pm
by vrg3
Hehe, yeah, it is technically possible to drop the WRX tank in place of the stock one... Technically.
Posted: Mon Sep 19, 2005 10:04 pm
by Subtle
Is it difficult to install in the the standard place on the ej22t set up?
Posted: Mon Sep 19, 2005 10:09 pm
by vrg3
Well, it doesn't actually fit properly there. We put it on snowboarded's car just to limp home from the racetrack after his stock tank broke. It was at a sharp angle and held in place with baling wire.
Plumbing-wise, it's not a big deal... BAC5.2 mounted his where the battery used to be (after relocating his battery to the trunk) just by extending the hoses. I don't think he managed to keep it quite high enough to keep all its functionality, though.
Basically, finding a good place to mount it is the only issue.
Posted: Mon Sep 19, 2005 10:33 pm
by Subtle
Thanks
The Honda battery is narrow and fits reasonably well into
the back right-hand compartment of the twgn.The panel in front of this had to be moved out a couple of inches.
Agree-- the former battery space doesn't provide sufficient
height.
In July Cliff2.2 was looking in to getting some fabricated.