Collant purge/return (?) line

[hjb981]

On the Northstar of my -97 DeVille, there is a thin (maybe 1/4") metal pipe that goes from the drivers side of the engine, over the engine (partly under the plastic top cover) and into the coolant reservoir. What does it do, what is it called, and where can I buy one? Mine is rusty to the point that I fear it will start leaking at some point if I do not change it.

[KHE]

That is probably the purge line. It may be available from a GM dealer but the way they have been discontinuing parts, I doubt it. It's worth a try. Since it is not exposed to road salt and moisture, it could look worse than it actually is. You could remove it, sandblast it, prime & paint it.

[hjb981]

I am pretty sure that it has corroded pretty badly. It has a section where it is much thicker than it should be, because of thick layers of rust. Where I live, it gets a good spraying of salt water through the grille almost every time I drive in the winter. My engine gets very dirty in the area where that line is situated. No matter how much I try to keep my distance, there will always be people changing lanes so that they end up spraying me etc. I guess the pipe could actually be replaced by a hose if the part is not available.

[Cadillac Jim]

I would think that the right size stainless steel brake line, a tubing cutter, and a tubing bender could do a pretty good job of fabricating a permanent replacement. I can't visualize this tube right now but if it has clamps that bolt down, these can be fabricated with sheet stainless steel and, if necessary, silver-soldered or attached with an appropriate adhesive such as hard-drying Permatex. If you have the old one in front of you and the car waiting with beauty cover off for trial fitting, this would be a crafts project for a couple of hours.

[hjb981]

I would think that the right size stainless steel brake line, a tubing cutter, and a tubing bender could do a pretty good job of fabricating a permanent replacement. I can't visualize this tube right now but if it has clamps that bolt down, these can be fabricated with sheet stainless steel and, if necessary, silver-soldered or attached with an appropriate adhesive such as hard-drying Permatex. If you have the old one in front of you and the car waiting with beauty cover off for trial fitting, this would be a crafts project for a couple of hours.

That is a good idea. I had some loose thoughts on doing something like that. I have access to proper bending and cutting tools (maybe even some leftover stainless steel pipes in the right dimension), since I work in a lab where we sometimes draw our own gas lines.

[Cadillac Jim]

Be careful of ordinary steel or copper piping, as those may not stand up to the salt and weather like stainless steel. Brake line is also more resistant to crimping shut when bent and thus easier to work, albeit stiffer, than the tubing normally used for indoor gas lines.

[rockfangd]

if you have a local u pull it yard they seem to be all over.

[Cadillac Jim]

The only u-pull-it place I found near Philly in South Jersey had no Cadillacs newer than 1990 or so. They also wouldn't tell you what they had and they charged admission. I should look harder.

[hjb981]

Finding parts in junkyards is tricky for me, since I live in Sweden. Not that many Cadillacs over here ... Otherwise I agree that it would be a good idea.