External thermostat thread savers

[nilknarf]

Hey all, I've done some searching (and a little finding) on the Pelican board and thought I'd pose the question: When using the thermostat thread savers, should I JB-Weld those babies up good to secure and seal them better, or just thread them on dry? I have managed to clean up the threads fairly well (note the stripped threads left by the old lines- marked by the green circle), but the threads that are left don't look fabulous (see the green arrow), and I'm not so sure I can clean them any more.



In the next shot you'll notice that I discovered a lovely flat spot that just might have an effect on this thermostat's ability to seal (marked by the yellow circle) and note again the crappy condition of the threads that are left for the thread savers to grab onto (marked by the yellow arrow):



So what I'm thinking is to mix up some JB-Weld and fill the channel in the thread saver (the spot marked by the pink arrow) and on the ruined threads of the thermostat in an effort to make my repair permanent:



So my question is this: is there any reason I shouldn't try my JB-Weld plan? Are there any tricks I should be aware of to assure maximum adhesion? (such as using phosphoric acid on all of the joining surfaces to clean and "prime" the aluminum?) I'd prefer to avoid buying a new thermostat if I can avoid it... and yes- I have 2 thread savers- one for each of the "downward-facing" lines.

Thanks!

Curt

[Steve]

Hmmmmmmm,..this is a toughie.

By all measures, one would normally replace the thermostat with either a good (better) used one or a new part, given whats at stake here. Looking at the center pic, the dent concerns me that it may be impossible to prevent that from leaking.

I suppose there is little harm in trying the JB Weld repair, provided that you doubly make sure there is no errant material in there that can migrate into the engine; that would NOT be a good thing at all and carries some expensive consequences.

For my part, I cannot take such risks with a customer's car so I either source a used one thats better that yours (and install a new cartridge) or get a new one. Too much risk to do this any other way.

Good luck and keep me posted.

[nilknarf]

Thanks Steve- I can definitely understand how you couldn't let something like this by on a customer car... there are a lot of NIB sub-$400 thermostats on ebay, are those generally Chinese knock-offs that should be avoided?

[cary]

I did mine with Steve's help about 10 years ago.
I used a thread saver and an adapter to install my AeroQuip oil cooling lines.

But I'd say that flat spot won't seal.
I'd try the JBweld. I'm thinking you try it and build a couple caps and pressure test it on the bench like an an oil cooler.
My .02c for this evening.

[Steve]

Hey Curt,

Based on long-term experience, I'm VERY picky about what parts I use, where they are manufactured, and who made it. There are a lot of substandard Porsche parts available now from variety of sources which makes it challenging when making purchases mainly based on price.

This is something I would never buy off E-bay unless the seller offered a factory part that was returnable, should be misrepresented.

Better yet, buy a new one OR a good used one from a reputable vendor who stands behind everything they offer.

[KTL]

Well i'd be lying if I didn't say my response is self-serving. BUY MY T-STAT?

http://forums.pelicanparts.com/porsche- ... -stat.html

But in all seriousness, I too would be wary of the t-stat savers when you don't have a good sealing surface. The sealing is all done by the spherical compression zone. So I don't care how many threads you've got. If that seat area is not uniform, it has HIGH potential to leak.

As you know it's a pesky job to get that t-stat in & out. Last thing you want is to spend all your time buttoning it up only to find what you didn't want to happen- a leak.

Did I mention my t-stat has a brand new regulator (Behr factory part) and new end caps for both the temp regulator and the pressure relief valve. Clean as my 7 week old baby boy Luke's bottom (after dad's changed his diaper- Lukes', not mine....) and could hardly tell from new.

[nilknarf]

I guess there are times when it doesn't pay to be such a cheap SOB! I think I kind of knew what I should do with this stuff from the start (but just didn't want to admit)... Kevin, I think I'll follow you up on your offer (I'll send you a note via your Pelican post)- I put a lot of work into making my engine right... it would be more than just a little foolish to put it at risk by trying to save a couple of hundred dollars in the wrong place. (and Kevin, being a fellow Dad who used to change diapers regularly, I believe you when you say that thermostat is clean! )

Cary & Steve- missed you at the last BnB... hope you can make it to the next one!

Thanks guys- another life saved!

[KTL]

Glad to help out and thanks to Steve for allowing me to sell one of my spares to Curt

[nilknarf]

I got Kevin's thermostat in the mail the other day and it looks great! While I was waiting, I cleaned up all of the threads in the lines and now I think I'm ready to install everything! Thanks for the good advice guys- this will be one less thing I'll need to worry about. For now I'll just run the trombone cooler I have and make plans to get a better one if needed.

[Steve]

Hey Curt,

The trombone will work for anything besides summer weather. For that time of year, you will need either a radiator cooler with fan, or the late SC tube cooler.