Bypass coolant tank?

91White-T · Post by **91White-T** » Fri Jul 29, 2005 11:41 pm

The nipple that goes to the turbo broke off on my coolant tank. How do I connect the hoses so that it will work without the tank? I dont care about the after cooling effect as I have a turbo timer... I looked at the diagram of the tank, but cant seem to make any sense of it.

vrg3 · Post by **vrg3** » Sat Jul 30, 2005 3:14 am

You still need a radiator cap, so you can't just connect the hoses differently.

I described how I took care of it here:

http://bbs.legacycentral.org/viewtopic.php?p=124825
http://bbs.legacycentral.org/viewtopic.php?p=110153

This could help you make sense of what's happening:

http://www.graphics.cornell.edu/~v/pics ... ooling.png

91White-T · Post by **91White-T** » Sat Jul 30, 2005 3:54 am

Thanks for the reply. I just have a couple of questions. The bottom large hose on the coolant tank (coming from the water pump, I believe) gets connected to the coolant line going to the turbo, right? The nipple on the new cap gets connected to the overflow tank, now what about the other fittings on the coolant tank?

vrg3 · Post by **vrg3** » Sat Jul 30, 2005 4:06 am

91White-T wrote:The bottom large hose on the coolant tank (coming from the water pump, I believe) gets connected to the coolant line going to the turbo, right?

Yes; that's correct. A brass 1/2"-barb elbow and a couple feet of 1/2" heater hose (to replace the tank-to-turbo hose) should do the trick neatly.

The nipple on the new cap gets connected to the overflow tank

Right.

now what about the other fittings on the coolant tank?

There's only one other fitting: the small one on the top of the back face of the tank, that currently goes up to upper passenger-side corner of the radiator. What I did was connect a piece of hose to that nipple on the radiator and put a ball valve at the end. This allows me to use it to fill the system and then block it off.

You might get away with just capping off the fitting on the radiator, but it may be hard to get all the air out of the system, since the radiator cap's not the at highest point.

91White-T · Post by **91White-T** » Sat Jul 30, 2005 4:10 am

Ok, that makes sense now. Thanks again

vrg3 · Post by **vrg3** » Sat Jul 30, 2005 4:14 am

No problem; good luck.

Natoe · Post by **Natoe** » Sun Jul 31, 2005 8:39 pm

i just put a legacy engine in my impreza, and would like to use my 1.8L radiator if possible, i have the extra radiator tank but no way to connect the top hose to my radiator.......
what im understanding from you guys is that i CAN block off the return line??
would it be better to block that off, or to remove the tank and connect the lines like you said. (remember i have a radiator cap on my radiator so that part doesnt matter if i remove it)
thanks!

vrg3 · Post by **vrg3** » Sun Jul 31, 2005 10:48 pm

Which line are you calling the return line?

Keeping the filler tank will help protect your turbo's bearings, so you may want to try keeping it. The way to do this in your case is:

Take the cap on your radiator and cut away the lower gasket. Then, take some 5/16" fuel line and use it to connect the nipple on the radiator's filler neck to the small nipple on the back of the EJ22T filler tank. Then use any old 5/16" hose to connect the nipple on the tank's filler neck to the bottom of the overflow tank.

91White-T · Post by **91White-T** » Mon Aug 01, 2005 12:43 am

Ok, I think I may have fixed the leak on the coolant tank, but now theres more problems. The expansion tank is bubbling, and the engine feels low on power, its also running a little hot, although not overheating. Now when the line blew on the tank, it dumped coolant all over the engine, cpould have have fouled the plug wire? I'm not ready to call the head gaskets blown just yet...

vrg3 · Post by **vrg3** » Mon Aug 01, 2005 2:32 am

If it's not head gaskets, do you need to burp the system some more?

Natoe · Post by **Natoe** » Mon Aug 01, 2005 3:20 am

by return line i mean the line that goes from the tank to the radiator. since there is no spot for it on my radiator i plugged it like in someone elses picture with a bolt and hose clamp.

today i filled everything up, first in the radiator cap till it was full, then closed it, then filled the tank cap till it was full and burped it out of there. the engine was cooling fine i believe, all the lines were hot, and the heater worked. can i leave it like this? why do i need change the overflow line?
thanks!

vrg3 · Post by **vrg3** » Mon Aug 01, 2005 3:57 am

Ah... yeah, you could plug it; it would just make it harder to burp the system. What types of caps did you put on each filler neck, and how did you connect the overflow tank?

91White-T · Post by **91White-T** » Mon Aug 01, 2005 6:28 am

How do you burp the system? Turbos have no burp screw, right?

vrg3 · Post by **vrg3** » Mon Aug 01, 2005 8:22 am

By "burping the system" I just mean getting all the air out. Typically it involves some idling the engine with the cap off, squeezing various hoses, allowing some cycles of warming fully up to cooling fully down, some incantations to Ra...

Natoe · Post by **Natoe** » Mon Aug 01, 2005 9:14 am

right now i just have both stock .9 bar radiator caps on, i idled with the top cap off for a while till it started coming out. for the overflow, i just have rad cap from the rad going to it like it was for my 1.8, and i dont have anything for the top one yet, but ill just run a hose to the same spot eventually, hopefully it wont be overheating and wont need that...

vrg3 · Post by **vrg3** » Mon Aug 01, 2005 9:44 am

On modern cars coolant flows in and out of the overflow fitting on the cap neck all the time; the car doesn't have to overheat.

Also, in order to get the post-shutdown cooling effect of the filler tank, you need the tank's cap to be the only active one.

You can either do what I suggested above, or put a higher-pressure cap on the radiator and tee the two overflow lines together.

Natoe · Post by **Natoe** » Mon Aug 01, 2005 5:15 pm

oh ok, so i just need to make sure i idle-cool the turbo for a while..
it just sucks because the nipple on the tank cap broke off.

vrg3 · Post by **vrg3** » Mon Aug 01, 2005 9:30 pm

Yeah, those tanks do break easily...

Wait, so you have a broken tank still installed on your engine? Did you plug the hole up somehow? Why not just remove the tank?

Natoe · Post by **Natoe** » Tue Aug 02, 2005 12:32 am

just the little overflow nipple is broken, not the tank...

im not going to remove the tank because i want the best cooling i can get with my radiator

vrg3 · Post by **vrg3** » Tue Aug 02, 2005 2:28 am

You mean the nipple on the back when you say "overflow nipple," right? Because the overflow nipple is the one on the filler neck.

But you've plugged the hole somehow, right?

Having the tank present is not improving your cooling. The fraction of a quart of coolant in the tank makes a negligible difference. And you're actually probably losing coolant out the overflow nipple that's not connected to anything.

Natoe · Post by **Natoe** » Tue Aug 02, 2005 10:03 am

i know i am losing coolant, but ill fix that before i drive it... its easier to have the tank there than to make fittings to reroute the lines.
ill move the overflow line from the radiator to the tank, and get a higher pressure cap for the radiator.. that should solve everything

vrg3 · Post by **vrg3** » Tue Aug 02, 2005 3:00 pm

The only fitting you'd need to get is a 1/2" hose joiner.

Even if you have a higher-pressure cap on the radiator, you should still tee the overflow lines together (just get a 5/16" tee and some 5/16" fuel hose). Caps open progressively, so there's still the possibility of losing coolant through the radiator's overflow fitting.

vrg3 · Post by **vrg3** » Tue Aug 02, 2005 3:01 pm

The only fitting you'd need to get is a 1/2" hose joiner.

Even if you have a higher-pressure cap on the radiator, you should still tee the overflow lines together (just get a 5/16" tee and some 5/16" fuel hose). Otherwise you'll be filling the top of radiator with air every time the system cools down.

Natoe · Post by **Natoe** » Tue Aug 02, 2005 7:52 pm

oh yeah, good point.. ill try and find a hardware store that has hosing and stuff

Natoe · Post by **Natoe** » Wed Aug 03, 2005 1:04 am

vrg3 wrote:Having the tank present is not improving your cooling. The fraction of a quart of coolant in the tank makes a negligible difference. And you're actually probably losing coolant out the overflow nipple that's not connected to anything.

i thought by having the tank there, convection currents cause the coolant to keep flowing to cool the turbo after you turn the car off... so it IS improving my cooling right?

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Bypass coolant tank?

Bypass coolant tank?