Coolant pipe corrosion

5.0 V10 50v biturbo - 571 bhp
Pinkfoot
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Re: Coolant pipe corrosion

Post by Pinkfoot » Tue May 21, 2019 9:43 pm

Doug_RS6 wrote:
Tue May 21, 2019 9:18 pm
Suggestion for people with only corrosion in the wheel arch area. I cut out the corroded section about 8 inches on each pipe. Using a small pipe cutter (needs to be small to be able to turn it) then pushed rubber hose on about 3 inches onto each pipe to get a tight fit as the pipe isnt flared. I then used a good quality clamp on each end. I also made some protective pads up and secured each hose together. I then liberally coated the metal sections with wax oil. Been good for 10 months so far and cost me around £8 for the hose and clamps. Wax oil I had in the house.
Nice and simple.
Hope it keeps good for you.

Doug_RS6
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Re: Coolant pipe corrosion

Post by Doug_RS6 » Wed May 22, 2019 5:17 pm

Seems fine and preferable to cutting up bee pipes to join anyway. I may at some point replace entire pipes if the engine is ever out.

Hadies
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Re: Coolant pipe corrosion

Post by Hadies » Mon Apr 13, 2020 4:08 pm

Doug_RS6 wrote:
Wed May 22, 2019 5:17 pm
Seems fine and preferable to cutting up bee pipes to join anyway. I may at some point replace entire pipes if the engine is ever out.
How has this fix held up for you Doug? I'm tempted to give it a go. Can you remember the hose diameter you used?
Thanks,
Hadrian

Hadies
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Re: Coolant pipe corrosion

Post by Hadies » Mon Apr 13, 2020 11:05 pm

Found the answer in a previous thread. Thanks Doug_RS6 and woodygo
16mm inner diameter for the rubber hose.
Pics and details here:
viewtopic.php?f=47&t=130134

Doug_RS6
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Re: Coolant pipe corrosion

Post by Doug_RS6 » Tue Apr 14, 2020 9:09 pm

Hadies wrote:
Mon Apr 13, 2020 4:08 pm
Doug_RS6 wrote:
Wed May 22, 2019 5:17 pm
Seems fine and preferable to cutting up bee pipes to join anyway. I may at some point replace entire pipes if the engine is ever out.
How has this fix held up for you Doug? I'm tempted to give it a go. Can you remember the hose diameter you used?
Thanks,
Hadrian
Holding up perfectly. They would of been better using rubber in the first place.

Doug_RS6
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Re: Coolant pipe corrosion

Post by Doug_RS6 » Thu Jun 11, 2020 4:34 pm

Revisited this today as I had only done one pipe for some reason and not the other although I thought I'd done both. So the higher of the two pipes was already done. Today I tackled the lower of the two.

Same procedure. Very small pipe cutter to cut the pipe, depending on how far down you're cutting you may bot be able to turn the pipe cutter fully. If this is the case a sharp junior hacksaw is your best friend once the pipe is mostly through.

Push the rubber pipe on as far as possible onto the pipe where it disappears into the engine bay. I managed to overlap where I made the cut by about 2 inches. Then put two small jubilee clips 22mm minimum diameter good quality and stainless steel.and then tightened both. Then take the remainder of the pipe which you have cut and cut it off leaving as much as possible but good metal. Push this into the rubber hose which is now mounted on the car. Then secure with 2 jubilee clips. Reconnect to the hose where it comes out of the header tank and refit factory clip.

Now I took an extra step.

I took some of the flexible plastic conduit, the type you use on wiring looms etc and sleeved it over each pipe to protect them from rubbing on each other. I then cable tied both pipes together over the conduit so they are secure and held in place. You loose the ability to use the factory clamp in the wheel arch but once the arch liner is back in place the pipes can't move anyway.

Hadies
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Re: Coolant pipe corrosion

Post by Hadies » Mon Jun 15, 2020 3:11 pm

Did this recently. Cheers for the tips Doug!
My pipe cutter was cheap and it was blunt by the time I'd finished cutting the second pipe. My forearms were on fire.
I was surprised at how thick and heavy these pipes are. So unnecessary.

Doug_RS6
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Re: Coolant pipe corrosion

Post by Doug_RS6 » Mon Jun 15, 2020 8:06 pm

Yes they do take a bit of cutting particularly the cuts that have to be made in situ. Fortunately that's only 2 cuts as the other ones can be made once the pipe is away from the car. One of mine was close to developing a hole an closer inspection (poking with a screwdriver) the other although not pretty to look at was solid. However I'm glad to have replaced both.

Duke1966
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Re: Coolant pipe corrosion

Post by Duke1966 » Sun Sep 27, 2020 10:28 pm

The pipes on my RS6 was so badly corroded under inspection, you could clearly see the coolant seeping from the section of the pipe exposed to the elements under the wheel arch. You have to ask why Audi designed these pipes to be located in such a hostile environment. It was my mechanic during MOT (@ Riverside Autos in Birmingham), that first highlighted it to me. He said removing them wasn't hard; however, re-installing wasn't as easy. One thing to note is he applied three layers of protective paint to the new pipe before re-installing them and suggested that I regularly have under the wheel arches cleaned of debris that naturally collects through everyday use. First-class job. 

cammmy
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Re: Coolant pipe corrosion

Post by cammmy » Sat Nov 28, 2020 2:41 pm

Started on mine today. As I have a compressor, I used a body saw with a fresh blade. Made quick work of both pipes. Just make sure you deburr the pipe after. I can imagine a pipe cutter would be a real pain to use in that space.

FYI, the hoses that join the pipe to the expansion tank are actually reducers, so you can't just just connect the hose directly between the pipe and the tank. You will want to order some 16mm barbed joiners ahead of time.

Those hoses seem okay on mine but I'm going to price up replacements anyway. I believe the part numbers are:

4F0 819 362 - £12 +VAT (Edit)
4F0 121 637 - £15 + VAT (Edit)
IMG_20201128_132755.jpg

cammmy
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Re: Coolant pipe corrosion

Post by cammmy » Thu Dec 03, 2020 7:10 pm

Fairly happy with this.
IMG_20201203_175612.jpg

Hadies
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Re: Coolant pipe corrosion

Post by Hadies » Fri Dec 04, 2020 2:27 pm

Tidy work man!

cammmy
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Re: Coolant pipe corrosion

Post by cammmy » Fri Dec 04, 2020 6:39 pm

Thanks, it's definitely not the worst job but I think the body saw really helped vs using a pipe cutter.

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