Thermostat Housing Fun - ZR-1 Net Registry Forums

SBAquaLT5 · 10-12-2018

Not an unfamiliar issue, but always fun. If I was more content with my heater not working, I would have left it alone.

I'm stopping by a machine shop tomorrow to see if I can drill and tap. A #6 extractor was no help today.

Anybody have success stories fixing this?

A26B · 10-12-2018

Both metals (aluminum t-stat housing & pot metal connector) are soft, so extra care needs to be taken to not damage the threads. EZ-outs frequently make removal more difficult because they expand the broken part, aka "dutchman," making it tighter. Drilling to remove is OK for straight threads, but the thread form used in this application is a tapered pipe thread. If done carefully, you can use a small chisel to drive one side of the dutchman towards the center, effectively collapsing it inward. The dutchman, being fragile is a benefit to this method. Once one side is collapsed& removed, the remainder is easy to remove using the same method at a different location. When completed, chase the threads with the proper tap size, being careful to not run it too deep. Again, this is a tapered thread (NPT), removing too much metal can be detrimental to tightening the new connector.

Taking the t-stat housing to a machine shop is a good idea, they will have all the necessary skills & tools. Screwing up the t-stat housing can make the repair more costly.

Corvettes White · 10-12-2018

Get a hold of this company: JERRY'S BROKEN DRILL AND TAP REMOVAL. Santa Ana, Orange County. I have used him for car parts. The aerospace industry uses him for their stuff. Reasonable costs. Small outfit. Nice man.
George

SBAquaLT5 · 10-12-2018

Thank you Jerry for the great advice; I was on the phone with you a couple days ago about this. I have not found a replacement housing anywhere, so being ginger with this one is the biggest priority.

I'll look into the Broken Drill and Tap Removal Business

Z51JEFF · 10-13-2018

Quote:

Originally Posted by Corvettes White

Get a hold of this company: JERRY'S BROKEN DRILL AND TAP REMOVAL. Santa Ana, Orange County. I have used him for car parts. The aerospace industry uses him for their stuff. Reasonable costs. Small outfit. Nice man.
George

Is this the guy that uses ultrasonic something the dissolve the broken part? I read a story in HOTROD Magazine years ago about a shop in L.A. that did this type of work.

Corvettes White · 10-13-2018

He has a lot of tools at his disposal. One "etches" away at the steel. One of the things he did for me was remove a #8 steel screw from a painted aluminum part. He made no promises
to no damage the paint and yet he did not damage the paint. As for being in a rag, IDK
George

jss06c6 · 10-13-2018

Machine shop would be good idea. A really good TIG welder can lay in some new metal and the machine shop can recut the threads. Would be interested to hear about the broken drill and tap guy for sure!

Sent from my XT1585 using ZR-1 Net Registry mobile app

10-12-2018	#1
SBAquaLT5 Join Date: Nov 2017 Location: Santa Barbara CA Posts: 51	Thermostat Housing Fun Not an unfamiliar issue, but always fun. If I was more content with my heater not working, I would have left it alone. I'm stopping by a machine shop tomorrow to see if I can drill and tap. A #6 extractor was no help today. Anybody have success stories fixing this? __________________ 1993 Bright Aqua Metallic # 027

10-12-2018	#2
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Thermostat Housing Fun Both metals (aluminum t-stat housing & pot metal connector) are soft, so extra care needs to be taken to not damage the threads. EZ-outs frequently make removal more difficult because they expand the broken part, aka "dutchman," making it tighter. Drilling to remove is OK for straight threads, but the thread form used in this application is a tapered pipe thread. If done carefully, you can use a small chisel to drive one side of the dutchman towards the center, effectively collapsing it inward. The dutchman, being fragile is a benefit to this method. Once one side is collapsed& removed, the remainder is easy to remove using the same method at a different location. When completed, chase the threads with the proper tap size, being careful to not run it too deep. Again, this is a tapered thread (NPT), removing too much metal can be detrimental to tightening the new connector. Taking the t-stat housing to a machine shop is a good idea, they will have all the necessary skills & tools. Screwing up the t-stat housing can make the repair more costly. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

10-12-2018	#3
Corvettes White Join Date: Dec 2003 Posts: 477	Re: Thermostat Housing Fun Get a hold of this company: JERRY'S BROKEN DRILL AND TAP REMOVAL. Santa Ana, Orange County. I have used him for car parts. The aerospace industry uses him for their stuff. Reasonable costs. Small outfit. Nice man. George

10-12-2018	#4
SBAquaLT5 Join Date: Nov 2017 Location: Santa Barbara CA Posts: 51	Re: Thermostat Housing Fun Thank you Jerry for the great advice; I was on the phone with you a couple days ago about this. I have not found a replacement housing anywhere, so being ginger with this one is the biggest priority. I'll look into the Broken Drill and Tap Removal Business __________________ 1993 Bright Aqua Metallic # 027

10-13-2018	#7
jss06c6 Join Date: Aug 2015 Location: Magnolia, Texas Posts: 884	Re: Thermostat Housing Fun Machine shop would be good idea. A really good TIG welder can lay in some new metal and the machine shop can recut the threads. Would be interested to hear about the broken drill and tap guy for sure! Sent from my XT1585 using ZR-1 Net Registry mobile app

10-13-2018	#6
Corvettes White Join Date: Dec 2003 Posts: 477	Re: Thermostat Housing Fun He has a lot of tools at his disposal. One "etches" away at the steel. One of the things he did for me was remove a #8 steel screw from a painted aluminum part. He made no promises to no damage the paint and yet he did not damage the paint. As for being in a rag, IDK George

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