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dzim
05-07-2012, 03:19 PM
I am new to the ZR-1 Net Registry Forum and new to ZR-1's. I just purchased my 1994 ZR-1 in March so my "terminolgy" may not be perfect!

A little over a week ago, I noticed that my ZR-1 had an anti-freeze leak on the left front behind the power steering pump. With the help of my mechanic (and best friend), we did a cold pressure test and discovered the driver's side coolant outlet tube was the source of the leak. It seemed that the likely problem was the gasket between the outlet tube and the plenum. I ordered the gasket and a set of bolts from Jerry's Gaskets (who has been great to work with - thank you so much Jerry). When we removed the outlet pipe, we discovered the gasket was in perfect shape. However, the outlet pipe was cracked. I then ordered a new outlet pipe - again from Jerry's Gaskets and replaced the cracked outlet pipe, put on a new radiator cap, pressure tested the system, and refilled with anti-freeze. We actually re-used the original bolts and gasket as they were in great shape.

My ZR-1 has been in storage most of its life. The odometer currently reads 9,985 miles. I thank the previous owners for preserving it, but I plan to drive and enjoy it. After replacing the outlet pipe, I drove it 400 to a Corvette Show in Kansas City this past weekend. The car performed flawlessly and even received a Best of Class Award for 92 - 96 C4's.

In the last two months, all fluids in the ZR-1 have been replaced and the car has been completely detailed - inside, outside, and under the hood. I fully expected to have "some issues" with a car that has been in storage. If it would have blown a hose, it would not have shocked me. However, I did not expect to have a cracked outlet pipe.

As you know, the outlet pipe consists of a rectangular housing with an attached pipe that goes to a radiator hose at the front of the engine. The crack is not in the pipe. It is in the housing on the front shorter side of the rectangle. At this point, the housing would appear to be its strongest as the bolt holes are recessed from the front two corners. The crack is all the way through this portion of the housing and continues around the joint where the pipe is connected to the housing and finally ends on the back side of the housing.

I have no idea what would cause the housing to crack like this. If the bolts were over tightened, I would expect it to crack in the corners around the bolt holes. I also have no idea how the pipe is connected to the housing or what would cause that seam to crack.

I know "pictures are worth a thousand words" and I have sent pictures to a friend who has volunteered to help me by posting them.
http://i407.photobucket.com/albums/pp152/QB93Z/Misc/Zimmerman-1994ZR1AntifreezeLeak006.jpg

http://i407.photobucket.com/albums/pp152/QB93Z/Misc/Zimmerman-1994ZR1AntifreezeLeak010.jpg

http://i407.photobucket.com/albums/pp152/QB93Z/Misc/Zimmerman-1994ZR1AntifreezeLeak003.jpg

I welcome your feedback and knowledge. If you have additional questions, I will do my best to answer them.

Thanks,
Dale Zimmerman
Lincoln, Nebraska
1994 Black Rose ZR-1 #113

Scrrem
05-07-2012, 03:43 PM
Dale,
I have seen a few of these coolant tubes crack and it has alway been in the square part of the housing. This part of the tube is cast aluminum and it is more that likely just something as simple as.... what Marc H described as a very pourious casting. Over time of heating and cooling, it cracks in this same place. Maybe someone else can chime in here, but that's my best guess anyway....
Rich

VetteMed
05-07-2012, 04:27 PM
yep, casting flaw would be my guess as to cause.

batchman
05-08-2012, 07:29 PM
Welcome to the forum and to ZR-1'dom!

Glad to hear your first issue is containable even if it is somewhat odd. Thankfully with this community there is a lot of help for anything that does come up.

I hope to make it out to your neck of the 'woods' some day for the SCCA Solo Nationals at the Lincoln Airpark. Some day. Of course if I get there with the ZR-1 you'll get to see what they look like 'dirty' ;).

Cheers,
- Jeff

oricale
05-08-2012, 07:30 PM
That was exactly what I had on the passenger side as well
I cut a groove right into the crack and jb welded it and sanded it to perfection
And wala!fixed

GOLDCYLON
05-08-2012, 08:45 PM
Not sure if this is the same side. There is however a single coolant outlet pipe on Ebay for $85


http://www.ebay.com/itm/Corvette-ZR1-LT5-port-left-water-pipe-coolant-crossover-/300659511936?pt=Motors_Car_Truck_Parts_Accessories&hash=item4600b41280&vxp=mtr

Is your storage location heated? This almost looks like frozen fluid expansion stress breakage vs. boss stress? I noted you live in Nebraska which is known to get a little cold. My thoughts are heat cold heat cold heat cold stress will cause this to happen to any flaw.

VetteMed
05-08-2012, 08:47 PM
Looks like the right part, has the bend for the AC lines clearance.

GOLDCYLON
05-08-2012, 09:02 PM
Looks like the right part, has the bend for the AC lines clearance.


Yea my thoughts as well its the right part decent price for a single as well. What do you think about my theory?

VetteMed
05-08-2012, 09:43 PM
Yea my thoughts as well its the right part decent price for a single as well. What do you think about my theory?

I dunno, never experienced a freeze-up of an engine, the antifreeze would have to be in rather poor condition to allow freezing solid, especially at this time of the year?

GOLDCYLON
05-08-2012, 10:17 PM
I dunno, never experienced a freeze-up of an engine, the antifreeze would have to be in rather poor condition to allow freezing solid, especially at this time of the year?

Concur however Florida and Arizona can't really comment on coldness lol.

VetteMed
05-08-2012, 10:28 PM
Concur however Florida and Arizona can't really comment on coldness lol.

Yeah, that's very true. :p

dzim
05-09-2012, 12:03 PM
I don't know if the car has ever been stored in a place that was so cold things would freeze. It has been in Nebraska for just a little over a year and I know that it was stored in a climate controlled building during that time period.

Prior owners were in Louisiana, Florida, and Pennsylvania. I have no knowledge as to what type of facility it was stored in at any of those locations.

My guess is that cold has not been much of a factor. Heat, time and a faulty casting is my best guess.

Dale Zimmerman

GOLDCYLON
05-09-2012, 12:15 PM
I don't know if the car has ever been stored in a place that was so cold things would freeze. It has been in Nebraska for just a little over a year and I know that it was stored in a climate controlled building during that time period.

Prior owners were in Louisiana, Florida, and Pennsylvania. I have no knowledge as to what type of facility it was stored in at any of those locations.

My guess is that cold has not been much of a factor. Heat, time and a faulty casting is my best guess.

Dale Zimmerman

Dale I agree your missing my point im saying it may be the hot and cold cycles coupled with a casting problem its not a boss or over tightening problem. Did anybody pressure wash the motor when it was hot?

dzim
05-09-2012, 12:26 PM
OK - I get it regarding the hot/cold cycles. You have a valid point. Pressure washing the engine when it was hot would be a bad thing from my point of view. I have been cautioned not to wash the engine as water gets into the "V" and will cause a problem with the starter.

It is conceivable that someone did at some time pressure wash the engine as the car has passed through several different owners. In addition to the original delivering dealer, it appears that it has been in the possesion of one Chevrolet dealership and two Corvette specialty sales operations.

Thanks for your feedback.
Dale Zimmerman

GOLDCYLON
05-09-2012, 12:35 PM
OK - I get it regarding the hot/cold cycles. You have a valid point. Pressure washing the engine when it was hot would be a bad thing from my point of view. I have been cautioned not to wash the engine as water gets into the "V" and will cause a problem with the starter.

Yep thats a 100% true statement. Ok well did you look at that new outlet pipe on Ebay? I attached the link. GC

dzim
05-09-2012, 01:22 PM
Yes, I looked at the coolant outlet tube for sale on eBay. However, I have already purchased a new one from Jerry's Gaskets and installed it on my ZR-1.

Dale Zimmerman