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Drip, Drip, Drip water torture!!!

914 Views 16 Replies 7 Participants Last post by  Dave M

Recently my MKIV has developed a very small but annoying leak on the lower radiator house outlet (see picture).
I have tried different type of hoses, clamps, etc and nothing seems to stop the leak.
My latest effort was to put RTV around the aluminum outlet, then slip on the hose adapter provided and then a silicone hose over that.
The leak is always occurring on the bottom of the radiator outlet. I have not observed any cracks or holes in the aluminum outlet, but maybe it is out of round?

Any suggestions would be appreciated.

The picture below shows the RTV that was squished out when I slid the hose on so I simply smeared it around the bottom. Not the prettiest and I realize that portion is not providing any leak stoppage. 馃槉
Engineering Gas Motor vehicle Auto part Cylinder
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That almost looks like a double hose clamped. Not right if it is.
The original setup that factory five provide worked for quite some time. It was made up of two hoses at the radiator outlet. An inner rubber hose that brought the diameter (kinda like a sleeve) up so it would match the Steel Hose and the larger rubber hose that would slide over both the corrugated steel hose and the hose over the outlet. I did notice that the outlet on the radiator has a slight "dent" inward, but it's before the "bead"( between the bead and the end of the outlet) so I wouldn't think it would have an effect. I have removed ( it was just ugly anyway :) ) what was in the picture and going back something close to the original setup. If it still leaks, I'll take the radiator out and take it to a shop to see if there is a defect or crack that I cannot see. I'll let you all know how it turns out.

Thanks All.
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To possibly save some time, why couldn't you take the corrugated flex off, make a step UP aluminum tube piece and connect it, keeping the radiator and tube diameter the same and the water pump inlet the same as well.
That's a possibility. I'm not sure where I could get a custom tube. A Radiator shop possibly? Factory 5 suggested this. Blue Silicone Hose, 1 3/4 x 1 1/2 inch ID Straight Reducer - Pegasus Auto Racing Supplies
A step up adapter, but still using the corrugated tube. I still think I will take the radiator to a shop and have them look at the outlet. It may be "out of round" and the clamps are simply not applying pressure in an area.

Thanks for all the suggestions!
An update:
I still had the leak with the original f5 config so I removed that. I took a piece of foam and pressed it onto the opening to see the shape. The bottom is definitely flatter than when the whole opening should be round. Because of that imagine there are a few spots in this area that are not sealing correctly. I'll be taking it to a radiator shop to see what they can do for me.
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It looks like you could go farther up the rad pipe with a longer hose. Maybe the pipe is better closer to the rad or you could try two clamps.
Unfortunately with the angle that the pipe exits the radiator, I've had it on as far as it will go, but keep the ideas coming. I have the radiator removed and I'll be taking it to a shop tomorrow. Wish me luck!
Could you use a radiator plug to straighten it from the inside? A radiator plug is a large rubber "cork" with a bold in the center. You tighten the bolt to expand the rubber to close an opening. Perhaps it will coax it back into shape.
I like that idea!
When solving a crime they say "follow the money", i guess when finding a leak "follow the fluid".... I have always been viewing the leak from under the car and only seeing the result of the leak and assuming that was where the leak was. But a leak may appear in one place but the actual problem may be elsewhere and traveling to a place that it becomes visible.
That's what appears to have happened here. I was trying to fix where the leak was appearing and did not realize that the leak was actually occurring elsewhere. So the Good news is the leak is gone from the outlet because it was never there. While under the car for about the 50th time, my shop light hit the radiator just right and I noticed a "greenish" hue from the weld above the outlet. When I reached up to investigate my finger came back with antifreeze on it. Not a lot but it was basically seeping from weld. When I placed a paper towel below the weld seepage the dripping stopped! It looks like when it was manufactured they tried to grind down the excess welding material and now it is seeping ever so slowly for about 6"-8" along the weld. It would then travel down the radiator to the outlet and then around it to the bottom and drip. So good news I know what is causing the drip. Now I just have to remove the radiator and take it to be fixed.
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Well鈥.. I went to 2 radiator shops and neither would work on the aluminum radiator. 鈽 They said they couldn鈥檛 warranty the work or guarantee that it would last and All aluminum radiators are brittle and don't flex like a hybrid plastic/aluminum radiator or a brass and copper ones. And the process to weld is at such a high temp, they couldn鈥檛 guarantee that it wouldn鈥檛 damage other parts of the radiator since the heat travels so fast with aluminum. Both shops said they stopped selling total aluminum radiators because they would last the year of the warranty and begin leaking and they were getting angry customers and it was a hurting their reputation. One shop said he could possibly custom build a copper and brass one, but he said it would be quite expensive and was even hesitant to do that.

Not sure what to do now (JBweld anyone?) . Any recommendations? Has anyone replaced their F5 supplied radiator with another aftermarket one?
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