AUX Heater Lines

[Da67goatman]

What has anyone used to replace the AUX heat lines running from front to rear?  Mine have rotted off twice now and i'm getting ready to replace them again, but want something more permanent.  The original aluminum rotted, so i replaced them with copper and they rotted as well.  Is there anything better?

[VileZambonie]

Have you checked for electrolysis?

[Da67goatman]

What is that?

[VileZambonie]

Read up on it and if you have any questions after I'll help you check for it if you don't quite understand it.

http://www.myradshop.com/information/electrolysis.htm

[Da67goatman]

Thanks for that info.  I'll check that when my dad comes home with his multimeter and report back, but i still need something to replace the lines with.  Any suggestions?

[VileZambonie]

I've never had a problem with them other than breaking. Rotting sounds to me like you may have electrolysis issues. Check that first, if you do have a case of electrolysis, repair it and then just replace the lines.

[Da67goatman]

The voltmeter read -0.16 volts with everything off and -0.14volts with accessories on so i don't think that electrolysis has any affect.

[Da67goatman]

Found out my heater valve is leaking so i have to replace that as well.  Can't believe how expensive they are.  best price i found was over $100.

My dad came up with a great idea for plumbing.  He recommended using PEX plumbing to run from front to back.  I think that's what i will end up doing, but i still have to figure out if i can rig up a control valve or if i have to buy an expensive new one.  I included a link so anyone not a plumber will understand what it is.

http://www.servicemagic.com/article.show.Pex-Pipe-A-Smart-Plumbing-Alternative.14539.html

[jaredts]

I don't know much about pex, but will it hold up to the hot coolant over years of use?  What about hitting a big pothole and jarring it repeatedly?  I have my doubts.  Aluminum and copper should both have been reasonable choices as they shouldn't "rot."  Both of those materials have proven themselves with hot coolant and last years in radiators, heater cores and under hood plumbing.  I would also be suspicious of electrolysis.  Did you check the voltage with every accessory on?  With the engine running?  Could there be an intermittent bad ground instead of all the time?

[autorepr]

I did conversion van and truck service at a chevy dealership and every conversion van with add on rear heat and air had rubber heater hose from front to rear. My folks bought a 93 Gladiator G-20 in 93 and it still has the original rubber going front to rear and so far no problems. I have replaced ALLOT of factory alum. lines with rubber hose and not had a problem. Just make sure you support it well cuz it'll droop!

I sure hope I didn't jinx myself bragging on the old Gladiator!!!!

[VileZambonie]

I HATE pex. Wait til it bursts

[Da67goatman]

PEX is rated for 100psi at 180° F so if it bursts i have bigger problems.  I think its perfect for this application.  Its unaffected by chemicals, its cheap, its easy, its color coded, and flexible.  I only worry about deterioration from UV light, but with it being under the truck wrapped in foam insulation i doubt it will harm it too much.

[VileZambonie]

When I bought my house the previous owners had added a zone in part of the finished basement and they ran pex through the existing wall. Well when it burst I had quite a mess on my hands. My best friend hates it as well and runs a company that deals with HVAC mechanical. It'll get brittle after time. I'm not saying it will matter for your rig but for what it's designed for, I have no faith in it. Look how many houses and buildings have the original copper piping for how many years? Mine had pex that lasted 6 years before it popped.

[autorepr]

Just clear my post up a little the conv. vans had crimped rubber A/C Hose not just heater hose for the A/C part.  The heater part was just regular old 5/8ths and 3/4 hose clamp heater hose. One continuous run.