Broken bolt, trying to replace t-stat! Help! - Page 2 - PeachParts Mercedes-Benz Forum

moon161 · #16 02-04-2015, 01:22 PM

PM SENT.

Diesel911 · #17 02-07-2015, 03:08 PM

Quote:

Originally Posted by leathermang

You are misvisualizing , a word I just made up, the thermodynamics of that situation .... as the heat will cause the opening to close... the metal follows the same ' path of least resistance' that many other things do... and will expand into the hole ... being more restricted by cold metal further away from the heated area...

However, heating the stud or broken bolt makes IT expand... which can sometimes crush the rust or corrosion between it and the head...so when cooled better allows penetrating oil to enter better...

It is also safer to heat the bolt or stud.... as many substances in addition to cast iron may suffer cracks due to uneven cooling after spot heating...

Sometimes the overly technical Engineering stuff is not what happens in practical use.

Items with holes in them when heated the hole generally expands and especially what you have an Aluminum surrounding Steel because Steel is not going to expanded as much.
A typical example if this is when pressing in an Engine Cylinder Sleeve you want the block hot with the Block Cyliner bore expanded and you want the Liner Cold and the OD contracted/smaller.

Even heating the outer metal and letting it cool helps because the Metal has in effect moved/displaced before it returns back it is not as stuck to the Bolt as it was.
Also Bolts are kind of a loose fit in the Holes and it us usally Rust or the Oxidized Aluminum that is filling the gaps between the Bolts and the outer metal.

Heat also allows the Penetrating Oil to seep in.

This Engineering issue is like the one where People say you should not use a Propane/Butane Torch on Aluminum because the Flame gets hotter then the melting point of Aluminum. That is true but in the course of My past career as a Mechanic I heated an un-countable number of Aluminum parts some cast and some extruded ones and I have never had the Aluminum Melt. It is likely the heat transfer is too fast for it to melt.

If what you say is true in practice heat still works unbelievably well if the person using the Heat is careful.

leathermang · #18 02-07-2015, 05:51 PM

Quote:

Originally Posted by Diesel911

....
A typical example if this is when pressing in an Engine Cylinder Sleeve you want the block hot with the Block Cyliner bore expanded and you want the Liner Cold and the OD contracted/smaller.......

The example at hand has cold metal all around it..... this was about spot heating... and that is going to cause expansion to make the hole smaller.

tangofox007 · #19 02-07-2015, 09:21 PM

Quote:

Originally Posted by leathermang

The example at hand has cold metal all around it..... this was about spot heating... and that is going to cause expansion to make the hole smaller.

So...if you heat a steel donut, does the hole get smaller or does the hole get larger?

leathermang · #20 02-07-2015, 10:29 PM

Quote:

Originally Posted by tangofox007

So...if you heat a steel donut, does the hole get smaller or does the hole get larger?

Really ? You use an example of the whole item being heated in a conversation about spot heating ?

edit... maybe I am reading your intentions wrong...
the item and the hole will get larger...
it is only the constriction of the cold metal around the spot heating in the original example which forces the metal to expand into the hole.

Lucas · #21 02-08-2015, 12:45 AM

Does the housing come off the block easily? I know on mine it's two studs and nuts. There is a gasket behind there.

You can also spin the rubber o-ring above the thermostat a bit and see if it seals. I'm embarrassed that I know that.

whunter · #22 02-08-2015, 01:31 AM

Quote:

Originally Posted by Nicole

Stupid enough to think the thermostat would come out easily.

Gotta take the kid to school early and all the car parts stores are closed!
I know this is a lost cause for tonight.

Taking the 3 bolts out of the housing for thermostat, the one closest to the passenger side broke.

The gasket is super shot out.

Is it possible to get just a new gasket?

I have the new thermostat.

Bolt is in awkward spot, no drilling possible.

What recommendations do folks have on what to do.

We're wikid rural and don't have an extra car.
So jerry rig temporary solutions are welcome!
Thanks

I need several angle photos, front, side top.

I may have a spare to swap with you.

.

tangofox007 · #23 02-08-2015, 12:20 PM

Quote:

Originally Posted by leathermang

Really ? You use an example of the whole item being heated in a conversation about spot heating ?

Kindly note that I applied no conditions as to the manner of heating. Feel free to apply heat in whatever manner suits the conversation.

tangofox007 · #24 02-08-2015, 12:24 PM

Quote:

Originally Posted by Lucas

Does the housing come off the block easily?

In theory, it's very easy. (Except that it's on the head and not the block.) Anyone going to the trouble would do well to consider replacing the bypass hose in the process.

Nicole · #25 02-08-2015, 02:07 PM

So we re-drilled the hole with a 3/16 diameter but we found(bit of a crime) then put it all back together to have it leak out the other gasket. Ordered one and went to put it back In only to have over tighten a bolt on the bracket in the absolute most impossible position. Now I need to go out and buy a 13mm deep offset box end wrench. Argh. Can drive it, but Lose coolant like crazy. C'est la vie

funola · #26 02-08-2015, 02:35 PM

The way this is going, I hope the next time you post, we don't want to hear it ran out of coolant/ over heated and need a head gasket.

leathermang · #27 02-08-2015, 02:38 PM

Well, I do not know how old you are...
but some of us who have been dealing with old cars for decades have had dozens and dozens of these type of seemingly ' thread unraveling' types of deals....
it is just part of old car stuff....and the fact that engineers were often not concerned with mechanics being able to address problems in a reasonable manner...

whunter · #28 02-08-2015, 02:52 PM

Quote:

Originally Posted by Nicole

So we re-drilled the hole with a 3/16 diameter but we found(bit of a crime) then put it all back together to have it leak out the other gasket. Ordered one and went to put it back In only to have over tighten a bolt on the bracket in the absolute most impossible position. Now I need to go out and buy a 13mm deep offset box end wrench. Argh. Can drive it, but Lose coolant like crazy. C'est la vie

Pictures of the damage would really help with diagnosis / advice.

.

Charlie Foxtrot · #29 02-08-2015, 06:07 PM

I've included a marked up photo (close up) of a typical mb t-stat housing where it is attached to the block. Hope this helps. I usually can snake a 13mm flex socket into the correct spot (yep, I use Snap On 1/4" drive 'cause they're skinny) or snake a box end down from above to break it loose. Once you have the housing off, you can warm it up with propane - gently, slowly, not too hot (NOT red, orange or any other color change - be gentle, this is aluminum pot metal, not cast iron) and then spray/wet the threaded areas with very thin oil - I like used trans fluid cut w/solvent, acetone works great. Use a few drops each cycle. Watch out for fire - use caution. You may have to do this several times before the fastener will loosen. You are trying to get the juice to wick into the voids between the threads. You may get lucky trying to tighten the fastener (very slightly) before loosening. You are trying to break years of corrosion from dissimilar metals jammed together. Remember to oil/grease the fasteners' threads before reassembly. good luck.

TnBob · #30 02-08-2015, 07:27 PM

Dont forget !