T-stat housing bolts

[Jerrys1990]

Good morning, I'm at work today off the clock to finally replace my thermostat. My issue is, the housing bolts are mega tight. I've been applying a good amount of force with my long handle ratchet and they won't break loose. Since the intake is aluminum, I'm afraid of breaking a bolt off or pulling the threads. They've been soaking in PB Blaster for an hour now. Anyone have some advice?

 

[movietvet]

I had same problem about a year ago on a customer's 89 K2500. PB Blaster for an hour is not very long. I have used Aerokroil for a couple days at random intervals, before getting something out. I tighten first, just a tiny bit. and then loosen just a tiny bit and spray spray. I was able to get the bolts out but did take a slight amount of aluminum with the bolts. I still had enough threads and showed the bolts to customer. I tapped the threads in the intake and chased the bolt threads. If you have a way to heat just the bolt head, and then try the tighten and loosen I described. If you can't, the intake removal is no big deal.

 

[evilunclegrimace]

Take a propane torch and slowly warm up the manifold and see if that will help

 

[Jerrys1990]

Well, I tried everything I could think of and got a whole bunch of advice from other folks, and everything failed. Both bolts are broken off now, and the truck is at work over the weekend. We used heat, all kinds of penetrating oils, vibration, etc. Even tried welding nuts to the exposed threads. So, she's stuck till Monday and I got a loaner to drive for the weekend. More bummed than mad....never had an issue like this working on the old small blocks. Now I know why everything else was replaced EXCEPT the thermostat!

 

[movietvet]

Dealing with steel bolts and aluminum intake is a PITA sometimes. They expand and contract at different rates and corrode differently. You can drill them out and tap to the next size up. There is plenty of room under there to clean out the debris. If you do that, use some anti seize on new threads. Not a bunch, just a dab. Luckily, access to do all this, is wide open. Or, spring for a new intake and gaskets.

 

[evilunclegrimace]

I put this stuff on every thing that is exposed to corrision or galvanic reaction.

You must be registered for see images attach

 

[PlayingWithTBI]

I put this stuff on every thing that is exposed to corrision or galvanic reaction.

Yep, it's pretty much the same thing (PTFE) as this stuff but, 1/10th, or more, the cost.

You must be registered for see images attach

 

[GoToGuy]

Depending if you want to keep it original or not, drill, tap installing larger bolts. Or install good quality helicoils not lager hardware. The other option find a machine shop with an EDM process for broken tooling removal. I feel your pain, part of life has been extraction of broken , machine screws, drill bits, taps. I have a crap ton of all different left hand easy outs, drill bits, tapered square, spline , and other last gasp ideas.
Good luck!

 

[thinger2]

The key to drilling out broken bolts is to approach the problem like an old school machinest would.
Start with a spring loaded center punch.
Also known as an "automatic" center punch.
The harbor frieght ones are garbage.
The ones sold under the "general" brand are good enough.
Basically a spring loaded ***** punch.
The human eye can discern plus or minus .002 when you are young.
Use reading glasses or a magnifying glass when you are old.
You want that first little indentation dead nuts in the center.
If it is off a bit? Angle the punch towards the center and push it again.
You can chase center with a spring punch.
When you are centered, take a larger diameter center punch and square it up on your new center and give a couple of taps.
That creates depth and pushes any distorted material out of the way.
I sometimes use carpenters nailsets to do this because they are hardened steel.
If it still looks good,
And you are happy with your centering.
Heat it with a map gas torch.
Your center punching has "work hardened" the divot that you need and that work harden will shred the cutting edge off of the next drill you need to use and that drill will not cut.
You have found center, now you just need to soften up the steel a little bit.
2 bucks worth of mapp gas will save 100 bucks on drill bits.
Any pocket or online machinist manual will tell you the major and minor diameter of any fastener and any threaded hole.
Even if you are off by + or - .010 as long as you are squared up and true when you drill you can calculate the largest possible drill you can use without hitting the threads.
If you are trying to use a screw extractor
Only use the square type.
And you need to leave more of the bolt intact.
They need some material to grab.
Dont stap a screw extractor in a broken bolt and put a wrench on it.
The same with taps.
They are hardened brittle tool steel and you can not side load them.
The only thing worse than a broken bolt is a broken bolt with a chunk of 02 tool or worse snapped off in it.
That snapped off chunk of tool steel is harder than any drill you own.
We ran aluminum 215 buicks in 225 class hyroplanes since I was a little kid.
I am the king of corrosion and broken bolts.
If it takes me 4 or 5 hours to drill a bolt and not have to helicoil it?
Well worth it.

 

[GoToGuy]

One biggee to remember when using an external heat source, torches of any sort, if your base is aluminum and trying to remove the broken is harder material. The Aluminum will melt , a lot faster, like solid, the next eye blink, there's a puddle running away. Wrecked that, got the T shirt.