WD -- Can't get thermostat housing bolts out... Thoughts?

[Will Herring]

I went to replace the temp gauge and thermostat on this old girl, and none of them would budge. The thermostat housing especially; I have soaked these bolts with penetrating oil off and on for about 2 weeks now and not so much as a squeak out of them.



I can see inside the housing with the upper radiator hose off, but the thing in there looks nothing like the replacement part I got from my local AGCO dealer.



So... Do I need to apply some heat? I'm leery of using too much, because that flange between there and the gasket seems like it could break really easily, and I don't imagine it'd be easy to replace that housing.
 

[acd17toy]

I have heated many of those houseings to get the bolts out. does not take that much heat on each one.
 

[BushogPapa]

You might try carefully heating the bolt heads and see if they move after they cool..
The New Thermostat may not look exactly like the Old one, but should fit..
You may just be ahead to twist the bolts of, drill and re-tap new threads..
Lube the threads for the next person..!!!
Ron..
 

[JMS/.MN]

When you heat the bolts, as they cool, put candle wax on them....soaks between the threads to loosen them.
 

[DiyDave]

Do the candle wax trick, and try tightening just a little teeny bit.
once you feel it give a little, turn the other way. Once it gives a
little in each direction, alternate directions, and oil as you remove.
 

[Will Herring]

Never tried the candle wax trick, but it seems like that would work pretty well. Guess I'll try putting some heat to it. I'm just nervous because that flange is so thin between the bolts and the gasket.
 

[Allis Dave]

I had the same problem when I changed the thermostat in my wd-45 a couple years. Seems to me that my flange was thicker and aluminum. The bolts had seized into the aluminum and I broke two off. After I took the flange off the broken bolts turned out easily with vice grips and the other one I slotted in turned out with a screw driver. Yours doesn't look aluminum though....
 

[Will Herring]

[S.C.]

I used an air die grinder with a thin cut off wheel and cut into
the gasket and through the bolts. Tried cutting the heads off
but still couldn't get it apart. I had the casting off the head too.
 

[Brian G. NY]

I'm with toy, try heating the housing with out applying heat directly to the bolt head; this will expand the housing and may allow the bolt to turn.
I did say "may"!!
 

[Dick L]

If the heads are still in good shape heat the bottom flange on the thread area and they will screw right out while still hot and the flange around the threads is still expanded.
 

[little sweeper]

I have had a lot of luck on my WC with apply heat and then spray PB Blaster on while it is hot. The hot metal will draw the lube in as it cools. Slowly and deliberately and barley wiggle in each direction, once it begins to move, heat and spray again. I like to heat things up and spray when i get home from work and give it a spray in the morning before I leave for a few days to get things started. Good luck!!