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Hose Identification Please!

chevyaddict

Well-known member
Joined
Jun 12, 2002
Messages
894
Location
Tucson, AZ USA
Corvette
1990 Convertible
I hope this isn't a really dumb question. I have a MASSIVE, and I mean MASSIVE water leak on my 90 corvette. RUNNING out of it so much so that it will empty the radiator completely in about 30 minutes. For the life of me I cannot locate exactly where it is coming from but I do have a suspect. My lower-most heater hose t's off (it goes from the heater box to the side of the water pump but before the water pump t's off), and there is a hose that appears to go down from the t on the passenger side and looks to hook to a metal line that is going under the engine, above the frame to SOMEWHERE. I can't seem to trace this on the other side anywhere though. Its weird. I think that is what is leaking simply because of the location. Its definitely not the lower radiator hose, and its not the water pump. I can't seem to find a picture diagram to show this. Can someone help me? Where does this go and why does it go into a metal line? And this has to be circulating SOMEWHERE to come back into the system but where? Am I losing my mind? ;help
 
I just found this picture! That metal hose running underneath... what is that? Where does it go?
 

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I think I just figured it out. It goes to the oil cooler I guess. I'm assuming this is a big pain in the butt to replace isn't it. How in the world would I do that without pulling the motor?
 
Hey! Long time, no see!! :)

I wish I could offer help but I'm a C3 owner, not a C4... Hopefully someone pipes in soon!!!

Mac
 
Hey! Long time, no see!! :)

I wish I could offer help but I'm a C3 owner, not a C4... Hopefully someone pipes in soon!!!

Mac

I know.... I haven't had time to do any tinkering on anything on the cars, much less browse forums! Been working my butt off actually. I think this is replaceable after inspecting it without too much tado.... I'm just wondering how the metal line got a hole rubbed in it from the frame. Seems odd to me. I'll have to bend the new pipe so it doesn't sit on the frame like that. ;) I'm still a bit suspicious though... that much water coming out just from this....
 
I know.... I haven't had time to do any tinkering on anything on the cars, much less browse forums! Been working my butt off actually. I think this is replaceable after inspecting it without too much tado.... I'm just wondering how the metal line got a hole rubbed in it from the frame. Seems odd to me. I'll have to bend the new pipe so it doesn't sit on the frame like that. ;) I'm still a bit suspicious though... that much water coming out just from this....
That does sound suspicious...

Too much work and not enough play isn't healthy but you already know that!

Mac
 
Maybe some 6 months ago, Air1 (another CAC member) had something similar happen with his hoses.

Yeah- leaking massive coolant is a killjoy for sure.
 
I do hope you don't have to much problem finding a replacement. OEM hoses are near impossible to find. You may have to replace the metal pipe with hose.Good luck.
 
OEM hoses are near impossible to find. You may have to replace the metal pipe with hose.Good luck.

That's exactly what Air1jpg had to do- he had to go with rubber lines after he couldn't find the hard line.
 
That's exactly what Air1jpg had to do- he had to go with rubber lines after he couldn't find the hard line.

Well, my power brake booster just went out on my IROC so I'll be tackling that first. Then, I guess I just have to start disassembling to expose the area. I still cannot tell for sure where its coming from. Very frustrating. I'll definitely post here when I figure it out!
 
That pipe is held in place by two studs that also hold the oil pan to the block.
I doubt the pipe could rub on the frame. There is a angle support bracket from the frame to the engine cross member that can be unbolted to get a better look at the pipe where it snakes upward on the passenger side.

The pipe attaches to a short piece of rubber hose then goes through the AC compressor bracket. The other end of the hose goes to a T fitting.
One end of the T fitting goes to the water pump.
Other end of the T goes to the heater core.

If the pipe has a pin hole leak and it's aluminum (which I think it is) it could be tig welded. If the pipe is steel it could be gas or mig welded.

The pipe is still available from Kurt White on E-bay or direct from his web-site. URL is below.


Chevrolet GM 86 91 Corvette 5 7L V8 Oil Cooler Pipe 10077544 | eBay


Blue lines in the picture below show the two brackets that secure the pipe to the engine oil pan to engine block studs.
 
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That is excellent information! Thank you! This is NOT a pin hole leak... it is a MASSIVE leak - that is why I am shocked that I cannot locate exactly where it is coming from. Literally my entire radiator will leak out of it, after its warm in less than 30 minutes.
 
t is a MASSIVE leak - that is why I am shocked that I cannot locate exactly where it is coming from. Literally my entire radiator will leak out of it, after its warm in less than 30 minutes.

If you see no coolant under the engine, pull the oil dipstick and verify the level. The coolant may be going into the oil pan because of an intake manifold gasket leak, or a blown head gasket.

Do you notice any white smoke from the exhaust?
Does the oil look like a chocolate shake?
Remove the oil fill cap and if it has brown colored goo that's an indication of coolant condensation.

Remove the spark plugs and verify non of them look like they've been steam cleaned which would indicate that cylinder is burning coolant.

You can also rent a radiator pressure tester from Autozone or Advance Auto parts.
You use a special radiator cap and pump the system to around 16 psi. Let it sit over night and there should be no pressure drop.

If that doesn't find the problem, take it to a mechanic. :L
 
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If you see no coolant under the engine, pull the oil dipstick and verify the level. The coolant may be going into the oil pan because of an intake manifold gasket leak, or a blown head gasket.

Do you notice any white smoke from the exhaust?
Does the oil look like a chocolate shake?
Remove the oil fill cap and if it has brown colored goo that's an indication of coolant condensation.

Remove the spark plugs and verify non of them look like they've been steam cleaned which would indicate that cylinder is burning coolant.

You can also rent a radiator pressure tester from Autozone or Advance Auto parts.
You use a special radiator cap and pump the system to around 16 psi. Let it sit over night and there should be no pressure drop.

If that doesn't find the problem, take it to a mechanic. :L

No, I'm pretty sure I explained earlier it is coming from the bottom of the car, obviously, but exactly where is the problem. Its not from the lower radiator hose or the water pump but somewhere else for sure. Not obvious out of a hose that I can tell but its spewing out all over the place! And I would NEVER take any of my vehicles to a mechanic!
 
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More help please

Ok. I am thoroughly frustrated now. It is NOT the oil cooler hose that goes under the motor and to oil filter area. Now, oddly enough, I had this all apart about two-three years ago when I had to replace my head gaskets. If anyone can send me a diagram or picture of all this in tact out of the car that would be great. The sheer amount of fluid spewing out of where-ever it is leaking has got to be something obvious but I can tell its NOT the lower radiator hose, NOT from the water pump (too much for the small seal hole) and obviously now NOT coming from that oil cooler line. The frame is all rusted where water has been coming from somewhere for a long time (this has been a small leak that gradually got bigger and bigger) but there is no evidence of it coming up higher in the motor. I really am stumped here and am trying to not just start taking things apart to gain line of sight for nothing. Any other thoughts?
 
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