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I need some advice on how to deal with the corrosion on all three ends of the metal cooling water tube that connects the water bridge to the coolant reservoir to the heater core.
I had to remove the tube today as part of my adventure in removing the long metal AC line that runs from the expansion valve along the firewall, fenderwell, and to the AC accumulator. I got that AC line out, by the way...
All three ends of the water tube had a healthy amount of surface rust, but none of it seemed terminal. The rust came off with no problems using a bench grinder wire wheel.
However, here is my problem: how to keep the ends of the tube from corroding again? I don't think a protective paint will withstand the coolant environment. I think a coating of antisieze will cause the hoses to slip off the ends of the tube under pressure.
I am not considering replacement at this point. The tube is still sound. A new one is in the neighborhood of $300. A used tube is $150 from 928 Intl. Even then, I don't know if I could get one without any corrosion.
I am flying blind here, all my prior vehicles have not had metal coolant tubes. Only heater cores and cast fittings in places. So, I am open to any and all advice.
Interesting how these things seem to corrode from the outside if yours and mine are anything to go by.
Ironically I had a spare one of these from my late S4 but do you think I could find it when I saw similar problems [worse in my case].
Your thread prompted me that in fact I did not think to pull mine for further inspection to see how it is getting on during my recent maintenance programme- perhaps I will pull mine and take a close look at it albeit I cannot see anything at the moment.
As for $300 to replace it surely some copper fittings and a bit of copper pipe can do the same duty assuming copper can stand up to the contents [well it has in my central heating system for the last 28 years]. It would not win a Concours competion but...?
Buy a new one. Unless the rust is chemically treated there will always be rust left in the divots of that pipe. With the wire wheel all you did was remove most of the rust but not all so it will come back.
I glass beaded ends on mine had it chemically dipped and replated in gold cadmium. I did three of them and used the best one on my 79. Having two extras
Etch it and replate to give thicker than normal plating. Know anyone who does their own plating?
Good idea! However, plating is not common in my area. Thanks!
Originally Posted by The Forgotten On
You could have it ceramic coated inside and out like some of the headers are or have it coated with something like Jet Hot.
Then you would probably never have to worry about it again.
Hmmm...good idea. However, I don't think that will be cheap.
Thanks!
Originally Posted by FredR
Interesting how these things seem to corrode from the outside if yours and mine are anything to go by.
Ironically I had a spare one of these from my late S4 but do you think I could find it when I saw similar problems [worse in my case].
Your thread prompted me that in fact I did not think to pull mine for further inspection to see how it is getting on during my recent maintenance programme- perhaps I will pull mine and take a close look at it albeit I cannot see anything at the moment.
As for $300 to replace it surely some copper fittings and a bit of copper pipe can do the same duty assuming copper can stand up to the contents [well it has in my central heating system for the last 28 years]. It would not win a Concours competion but...?
Good point, Fred. Usually, when I look for something, I don't find it.
As for fabricating a new one, my fab-fu skills are limited. Thanks, though!
Originally Posted by kiwiokie
POR-15 is apparently good for 450f.
Ooooooh...had not thought of that. Thanks!
Originally Posted by Imo000
Buy a new one. Unless the rust is chemically treated there will always be rust left in the divots of that pipe. With the wire wheel all you did was remove most of the rust but not all so it will come back.
ImoOOO, very good point about the rust. However, at this time I am not quite ready to pay $300 for a new one. Yet.
Thanks!
Originally Posted by V2Rocket
"paint" the whole thing in spray-on undercoating/bedliner?
Not a bad idea! How well does that hold up to antifreeze?
Thanks!
Originally Posted by Guy
I glass beaded ends on mine had it chemically dipped and replated in gold cadmium. I did three of them and used the best one on my 79. Having two extras
I do have access to a bead blaster. However, plating is not common in my area.
Thanks!
the ends of this pipe on my car are corroded too; I'm considering sheathing the inside for an inch or so with a smaller diameter copper tube insert. JB weld for an adhesive.
Seth- you shared pictures of some cleaning efforts at work. Based on those, you have some fab capability using some surplus SS tubing and a handy bender. We're it me in that environment, a government project would commence.
Braze the ends to cover them in bronze brazing rod. Or, maybe even silver solder. Or maybe even plumber's solder. Now that you have the ends pretty well cleaned up, coat them with plumber's paste flux, then heat the ends up with your mapp gas torch and melt solder on them, then while it is still hot and molten, wipe it off real quickly with a heavy rag. Wear gloves.
Last edited by Jerry Feather; 04-09-2017 at 11:24 AM.
04-07-2017, 12:42 AM
Corrosion on metal water tube ends
