rolex11

So guys, I can’t believe I found where this coolant leak was.

Photo A is to show where the general area is. It’s the 2 coolant hoses under the coolant reservoir tank where the arrow is. The top black one is rubber and attaches to the bottom of the coolant reservoir tank held on by an OEM hose clamp. The bottom hose is a silver metal hard coolant hose. The black one runs over top of the silver one and they actually touch.

Photo B is a close up of the 2 hoses. In this photo you can see the top black hose that my finger is pointing to, and the OEM hose clamp that the horizontal arrow is pointing to. The vertical arrow points to the lower silver metal coolant hose.

So what’s the issue here? Well, the clamp as it is shown in photo B is after I rotated it counter-clockwise about in inch. The problem was that when it was rotated an inch clockwise, the tab on the clamp that sticks out was butted up against the lower silver metal hose. Over time the vibration of these hoses has caused the tab of the clamp to slowly file into the lower metal hose until it finally wore thru. If you look close you can see the rectangle hole the clamp has worn in the lower metal hose (the vertical arrow is pointing to it.) If I squeeze on one of the rubber hoses I can see coolant shoot out of it.

Amazing!

So here is my question guys, how do I patch this metal coolant hose?

I’m hoping to not have to replace it because it runs pretty far up to the front of the car and looks like the engine would need to be dropped.

1. Can it be spot weld it?
2. Can I glob some JB Weld on it?
3. Could I use metal tape?
4. Could I use some sort of patch (perhaps rubber) and hold it on with a worm hose clamp?

My guess would be to do #4, rubber patch, then press it up nice and tight with a worm hose clamp. JB Weld would be my second, although I would have to see how heat resistant it is.

Looking for ideas….

Remember it’s a metal coolant hose so I’m assuming it gets quite hot.

Hope I explained it well enough so you guys understand.

Thanks.

Hurdigurdiman

The main problem with each of your suggestions is that coolant would still be in the pipe to be repaired. If you can clear that pipe of coolant then apply either #1 or #2. Good luck.

Youri Ko

Clean well, grind a little, then JB weld. After some rubber and clump

rolex11

Got JB Weld, the original 2 two tubes and mix together kind. Says it's good to temps up to 300 degrees and 3600 psi.

As far as coolant still being in the hose. Since it's on top and not under pressure, I should be able to sand the area, clean it, and apply it without any coolant getting in the way. Says to leave cure over night.

I'll probably put a worm clamp with some rubber under it, just to be safe.

Anyone know if I need to burp the system? Would air have gotten in?

Hurdigurdiman

I would suggest you top off as normal. Then manually lift the pressure relief valve as you are warming the engine. Check level again and all should be well.

5CHN3LL

If I was going to repair this in situ, I would have gone with something like your #4 - RTV silicone, a rubber or silicone patch a couple of inches square, and a small section of slightly larger pipe to put directly above the leak - and a large number of zip ties to compress the rubber to the surface of the pipe. If you use hose clamps, don't get too crazy with the torque - it would suck to buckle the pipe you're fixing.

Good luck with the repair.

rolex11

Today at noon I applied JB Weld. See photo.

First degreased it, then sanded it, then wiped it clean and applied.

Not sure if it's gonna need a clamp. Kind of hard since its on a bend and the clamp won't set flush since the JB Weld is raised.

I put some on a test piece of pipe to see how bonded it is. Won't know til tomorrow, needs 24 hours to cure.

I'll look at the test piece first, to see if I'm happy with that. Then I'll monitor the real patch for the first dozen or so heat cycles.

Youri Ko

Nice job, should hold well.
To burp, my advice is :
-Top off to maximum
-Lift the relieve valve and drive around for a day or two, keep a 2L bottle of Coke handy with premixed in it
-Every time you stop, go check the level, refill carfully - you'll be surprised how much air you can get out this way

rolex11

Thanks.

Will update. Saw one guy on Youtube that claims JB Weld does not hold up around coolant, turns to mush he claims. Others report it works well.

We'll see.

sjg1138

Do you think that the JB weld was able to work its way to the inside of the pipe through the leak hole? I would imagine that if the JB weld is on both sides of the hole (inside and outside the hose) it will be incredibly strong.

rolex11

No way to tell.

The wear notch on the metal was about 10mm x 4, about the same size as the tab on the hose clamp that caused it. However, the hole was just a pin hole.

Unless this metal coolant pipe has 3-4 mm steel, which I'm positive can't be the case. I believe the tab of the clamp actually pushed the metal inward and caused a dent. The dent is actually about 3-4 mm deep, and I know the steel of this pipe is not that thick. The dent was probably there for quite some time, and finally weakened enough from vibration and heat cycles causing a small hole to finally happen.

5CHN3LL

It still looks like the clamp is contacting the pipe...maybe a little bit of neoprene to go between the two surfaces?

DBJoe996

Well, one good thing about sharing this type of problem - I just went and checked mine to see if was doing the same thing. What I noticed is there is quite a bit of separation between that hose and clamp and the metal pipe. I also noticed about 1/2 down the visible part of the metal pipe on the left there is a hose holder clip for the metal pipe attached to the wall of the engine bay. Any chance your metal pipe has come out of that and is riding high allowing contact? Part #34 here http://www.autoatlanta.com/porsche-p...section=105-05
BTW - spin that clamp so the pointy parts aren't facing the metal pipe. Oh yeah, and what Schnelly said, maybe if you can't fix the separation, zip tie some neoprene or a piece of coolant/radiator hose over it.

rolex11

No. Check out photo B in my first post. It's not the band of the OEM clamp hitting the other hose, it's one of the tabs of the clamp that are sticking out. The tabs you squeeze together with the special tool to open it and remove it. You can see it in the photo. It's just that in photo B I already rotated it counter-clockwise so the tab no longer hits the metal hose. Imagine rotating that clamp and having that tab press up against the metal hose. If you notice the dent in the metal hose is the same shape as the clamp tab.

So thank for the heads-up, but there's no contact anymore since I rotated the tab.

5CHN3LL

Yeah, I saw that the hole was caused by the poorly oriented clamp, but I wasn't able to see if there was still contact between the band and the coolant pipe. In your "after" photo, the flash shadow made it difficult (at least for me) to see if there was a gap or not.

Keep us posted on how long the repair holds - hopefully forever...