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Kinked coolant pipe -- what is correct geometry? by oneinch
Started on: 02-12-2021 10:48 PM
Replies: 26 (390 views)
Last post by: ericjon262 on 02-26-2021 03:04 AM
oneinch
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Report this Post02-12-2021 10:48 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Both of my coolant pipes are kinked at the rear wheel well. Common occurrence I guess. I've never seen what a perfect pipe is supposed to look like. I plan on having the kink cut out of the pipe and a new section of tubing welded in place. My question is (using my picture for reference): I should have the coolant pipe corrected so that both of the red lines become one line, yes? The coolant pipe should be straight, except at the very end where it is supposed to bend upwards slightly.

In case anyone is wondering, I replaced my internal hex drain plugs with external hex drain plugs. My original plugs came out easily, but I much prefer using a 7/16" wrench to loosen and tighten them.

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Report this Post02-13-2021 08:42 AM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
The pipe is supposed to be straight, right to the point where it "kicks up" at the back.
With that said, if you're just going for functional, as opposed to "concours/show worthy", anything close should be fine, as long as you can tap the sides in where it was kinked, in order to mostly restore the cross-section.
I had a set that looked nearly that bad, and was able to mostly straighten it, and used a vice and a hammer to "massage" it almost round.

Barring that, Rodney Dickman sells repro pipes, that contain the "under the door" section, all the way to the rear. Since the front sections are almost never damaged, the new rear sections are spliced into the existing fronts. I was only recently made aware of these.

http://rodneydickman.com/pr....php?products_id=495

[This message has been edited by Raydar (edited 02-13-2021).]

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oneinch
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Report this Post02-13-2021 08:59 AM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you Raydar. Straight or straighter they will be. No, not going for the concours thing. I just don't want overheating problems.

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[This message has been edited by oneinch (edited 02-13-2021).]

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Report this Post02-13-2021 09:13 AM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by oneinch:
...
I just don't want overheating problems.


Strangely enough, I bought an 88 coupe a few years ago. The passenger side coolant tube looked a lot like yours.
I was able to drive the car around, even in the summer, and it never seemed to overheat. But I had access to a spare tube, so I swapped it.
I then straightened and hammered out the original, and gave it to one of the guys in our club who also needed one.
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Report this Post02-13-2021 10:16 AM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Straightening that tube by bending/hammering may work but my level of comfort in doing that is not 100%. There is a phenomenon known as "work hardening" that tends to make the material more brittle and thinner when it is bent a few times, especially so on old material that has been heat cycled. Will this work on your pipes? Most likely yes, but being the stickler that I am for precision my tendency would be to replace the pipes.

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Report this Post02-13-2021 01:01 PM Click Here to See the Profile for steve308Send a Private Message to steve308Edit/Delete MessageReply w/QuoteDirect Link to This Post
Has anyone considered going to a muffler shop with a tubing bender and just having them made? I would think that even if it was made in sections and then connected by welding or joining with silicone sleeves it would be feasible.
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Report this Post02-13-2021 01:29 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
A muffler shop is where I'm going. I'm only going to have a short section welded in. Cut out the kink, weld on a replacement. These tubes are a non standard size. I measured my OD to be 1.317"~. My plan is to use seamless SS tube with an ID of 1.402". The resulting 3/64" gap should be filled nicely by the weld.

Any welding place can do this. I'm looking for a TIG weld with SS filler.

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Report this Post02-13-2021 04:43 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by oneinch:

A muffler shop is where I'm going. I'm only going to have a short section welded in. Cut out the kink, weld on a replacement. These tubes are a non standard size. I measured my OD to be 1.317"~. My plan is to use seamless SS tube with an ID of 1.402". The resulting 3/64" gap should be filled nicely by the weld.

Any welding place can do this. I'm looking for a TIG weld with SS filler.



You can sometimes find welders on Craigs List in your area. I used a guy a while ago in your area but lost his number. A welder must be pretty skilled to weld on that thin stainless tubing.

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Report this Post02-14-2021 03:21 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
Welding other tubes to this often fails. Weld "rod" and new tube isn't same metal and have problems because of that.

Cut at crimp.
Expand the tube.
"splice" w/ hose.
Many sure short end is tie to frame to support it and can't "blow off" because any tube w/o "hose lock bumps" easily blow off/out of hoses.
Use search.

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Report this Post02-14-2021 09:31 AM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'll be sure to inquire about that theogre. I know next to nothing about welding. My plan is to use a muffler shop thinking they weld thin wall tubing regularly. They often work with stainless steel. I'd like them to back purge the weld as well. Hopefully in the end I have a quality job done. I think I will have. We're talking metal here. Nothing special. It can be welded. If it isn't, it's the welder's fault.

Worst comes to worst, I buy the repair tubes from Rodney. In any case, I want the kinks gone.

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Report this Post02-14-2021 11:34 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
Don't think Exhaust repair = Coolant tube repair. Many exhaust shops won't touch this for many reasons...

Exhaust repairs including welded joints doesn't matter when seams leak and often they do.
OE welds at car factory are done before most to all parts are in the car. Often done by "robots" too even many years ago likely many Spot weld bots.
But 3rd party welds and clamps often have gaps and leak some to a lot and most owners have no clue.

Most exhaust welds are on overlap parts because pipes are make for use w/ clamp on joints too. If the overlap is tight, the inner tube expand a little more when hot and can close a small leak while car is running.
OE welds are cheap and fast just to save time and money for GM. 3rd party is similar issue.
If you see clamps, Most factory exhaust clamps seal way better because made different then most clamps used by DIY and even "Pro" shops. Most aftermarket clamps don't load the joint evenly and make leaks.

I've seen many exhaust repairs leaking a little to a lot to fail but where they happen and when can mean not easy to see or hear. Even crack exhaust manifold and other pipes upstream of the cat may not make much noise and pass E-testing and/or not set Codes until crack is big. But leak there can let Air inside and F'd up O2 sensor reading causing other problems and eat more gas.

Many coolant systems can still have problems even when metal tubes overlap and welded or clamped...

Coolant leaking even a tiny drop per mile can cause a lot of problems fast and leave you stranded.
Coolant has ~ 16 psi in the system when hot vs exhaust runs < 2 psi at any time and very tiniest coolant leak w/ cold engine, like tiny and you can't see w/ cold engine, can dump faster and more when hot and tries to build up system pressure. Is also why iffy coolant hoses & seals often only leak at joints w/ hot engine and need a pressure tester tool kit to find them w/ engine cold and safe to work on.

Mismatched tube material can have different expansion rates and stress for this could crack or fail at weld points or anywhere on or near a patch. more so have more system pressure to handle too.

Worse, If you weld the coolant tube... Know that this damage is very common and next time you let any shop to do any work can quickly wreck the tube again and welded repair can break not bend.
Is common because many places use Jacks, Jack Stands, and most Lifts Wrong to lift a Fiero.
And not only the coolant tube but the plastic rocker panels and small rear panel in front of tire is damage for same reason.
Open door and look at where that small panel meet the door jam. When the panel doesn't sit tight to jam then whole area is wrecked most by jacking/lifting wrong.
If rocker is cracked/broken there often have same thing happen.
(Note that Lowered cars can see same problem.)
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Report this Post02-14-2021 12:07 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
I discuss things at the weld shop. Welding is the best way to repair. As with any repair, poor work results in poor results. With welding, the material and conditions won't be the problem. Using rubber hose and clamps certainly works. It's not the route I'm choosing to go first. I don't think this repair will be a problem for a competent welder. The first problem for me to overcome is being an incompetent judge of any welder. But hey... ¯\_(ツ)_/¯
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Report this Post02-15-2021 11:39 PM Click Here to See the Profile for reinhartClick Here to Email reinhartSend a Private Message to reinhartEdit/Delete MessageReply w/QuoteDirect Link to This Post
Regarding different metals, why not 1) attempt to straighten pipe. If works, done. If kink remains, remove pipe and just cut the pipe at the kink. Straighten ends. Now have a welder use stainless flux to weld the stainless pipe. Done
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Report this Post02-15-2021 11:57 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just turned my pipes over to a welder today. I expect to have them back end of the week. I have high expectations. I'll post pictures of the finished job. My pipes weren't leaking, but we noticed a few minor imperfections here and there in the pipes. The welder is going to fill these spots. The pipe will be sanded down and should look next to new. We'll see.
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Report this Post02-16-2021 12:56 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just picked up my welded and repaired coolant pipes. I'm am completely satisfied in everyway with choosing this repair method and the welding that was done. Cost was just under $350; $320 for the welding and under $30 for a repair pipe from McMaster Carr. This price is extremely competitive to the DIY repair tubes from Rodney Dickman. His pipes will 100% make the repair and would have been less expensive ($300 + shipping), but I wanted a welded solution. Sure, there are even less expensive solutions. This could be considered the high end on the repair scale.

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Report this Post02-16-2021 02:18 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
Good show! Nice work. Very nice.
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Report this Post02-17-2021 02:06 AM Click Here to See the Profile for reinhartClick Here to Email reinhartSend a Private Message to reinhartEdit/Delete MessageReply w/QuoteDirect Link to This Post
Glad you're happy with the result. I'm a bit confused why such a big patch was needed for just a kink. Did he give a reason why he couldn't cut at the kink and just weld once (Rather than twice) after straightening? Would have looked nearly perfect without the added turbulance of multiple changes in diameter (small, big, small).

Also $300 seems excessive for just a couple seems. The local welder I used before COV19 would give me an hour of welding for $150. This shouldn't have taken more than 15 minutes.
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Report this Post02-17-2021 02:54 AM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
The reason for the big patch is because you have to cut out the crushed pipe. Cutting through the middle of the kink, trying to reshape the tube, and then butt welding it back together - while possible in only a perfect world - is not the way to do it. You'd never get the two pieces to match up. Four inches or so was cut out...back to round tube. The repair pipe is 1.5" OD / 1.402" ID is a little bigger and slips over the original. Hence the two welds . If there was a turbulence scale it wouldn't even register. It's now twice as good as it was, if not better. As far as price, your price may vary. I guess I hired the most expensive welder in the world. Que sera sera.

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Report this Post02-17-2021 09:39 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by oneinch:

Cutting through the middle of the kink, trying to reshape the tube, and then butt welding it back together - while possible in only a perfect world - is not the way to do it. You'd never get the two pieces to match up.


I've had exactly that done... it's not that difficult.
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Report this Post02-17-2021 10:00 AM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like I'm being challenged. It's the nature of the internet. Between the two methods the way I had it done is stronger and superior. I'll take best over good every time I can.

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Report this Post02-17-2021 03:13 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Working in aerospace I can say better is the enemy of good enough

Unless you're planning to jack the car up on the coolant pipes, they were already strong enough
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Report this Post02-17-2021 03:43 PM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm well aware of that saying. It's a good one and so true. In my case the results were worth the pursuit.

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Dennis LaGrua
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Report this Post02-17-2021 07:08 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Looks like an excellent job that will last but at a premium price for less than an hours worth of work. You paid the guy for what he knows and his skill, not for what he did. We have Hobart Handler 190 220V unit that we use to weld exhaust with Stargon CS gas and .030 mig wire but welding on thin stainless is an art in itself. My guess is that he Mig welded with Stargon SS gas ,a special mix of Argon,CO2 and Nitrogen. I would not make an attempt to weld this job as it needs to be perfect and leak free. My approach to this repair would have been braze welding. It works great on thin SS material. I have brazed a few broken EGR tubes with success. The bottom line is that you got the job done right.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
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87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
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Report this Post02-17-2021 10:14 PM Click Here to See the Profile for LarryinkcSend a Private Message to LarryinkcEdit/Delete MessageReply w/QuoteDirect Link to This Post
Nice looking repair. It's your car, you're happy with the result. That's really all that matters.
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Report this Post02-23-2021 06:05 AM Click Here to See the Profile for reinhartClick Here to Email reinhartSend a Private Message to reinhartEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by oneinch:

Sounds like I'm being challenged. It's the nature of the internet. Between the two methods the way I had it done is stronger and superior. I'll take best over good every time I can.



Hi thanks for the reply earlier. I wasn't intending to challenge so much as understand the reasoning for both myself and those that encounter the same situation in the future. If someone does a search for coolant tube repair and thinks that this is the best way (which it might be) with others offering alternate ideas to flesh out a possible improvement going forward it would to me and likely others be that much more helpful.

I was thinking that the easier and more "factory" look would involve a single cut at the kink then using an exhaust pipe expander inserted into either end of the cut which should work well to create a near perfect round opening again that could be welded to as easily as the welds in your solution. And if my idea sucks I'd love to hear that as well (which you did and one other said it was a valid idea).

Again I'm happy you like your result. I was just trying to further discussion as to the pros and cons of your method vs others or the benefit of those that haven't done this yet but will in the future.
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Report this Post02-23-2021 01:49 PM Click Here to See the Profile for RandomTaskClick Here to Email RandomTaskSend a Private Message to RandomTaskEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by theogre:

Welding other tubes to this often fails. Weld "rod" and new tube isn't same metal and have problems because of that.

Cut at crimp.
Expand the tube.
"splice" w/ hose.
Many sure short end is tie to frame to support it and can't "blow off" because any tube w/o "hose lock bumps" easily blow off/out of hoses.
Use search.




The filler material is chosen off the material you're welding. I'm pretty sure these are SS units. It's easily weldable provided the correct filler material/guidelines are used.
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Report this Post02-26-2021 03:04 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by RandomTask:
The filler material is chosen off the material you're welding. I'm pretty sure these are SS units. It's easily weldable provided the correct filler material/guidelines are used.


This.

I welded mine up no prob with some 308 filler on my TIG.

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