Are you using a OEM thermostat housing gasket? Only use the OEM seal, it seems to be thicker than the aftermarket ones. They are meant to be installed with no extra sealant

Well, I called the nearest machine shop and they said it can't be re-surfaced, I have to get a new one. I'm not really sure she understood what I was talking about. I don't see why it couldn't be re-surfaced, but I wasn't going to argue. I hate being on the phone as it is.
79Mercy, I did use the OE gasket. Three of them, so far ... I tried it with and without water pump housing sealer.
Maybe I'll go to the junkyard this weekend. Of course, if I do find one that will entail having to remove another York AC compressor, in the cold.:rolleyes:

How about cutting a channel into the housing and using thick copper wire the way they used to o-ring cylinder heads in the heyday of shade tree hotrodding?

Sixto
87 300D

Yeesh
 

The person may have been thinking thin modern pot metal or plastic.

Take it in person to a couple of local machine shops, the phone won't work.


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Maybe you can resurface it yourself the way 1960mog resurface the oil pump housing surfaces in this post - http://www.peachparts.com/shopforum/2857396-post3.html

Sixto
87 300D

YES
 

That will work. :)

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Thanks guys. Hopefully I'll have time to swing it by one engine shop on the way to work. Tomorrow I should have some time to play around with sanding it like in the oil pump example. I like the idea of using the floor as a flat surface, for some reason I hadn't thought of that! I also think maybe I haven't been using a course enough sandpaper. I was trying to use a sanding block with 600 grit ... I'll pick up something rougher.

Umm
 

600 grit may take a few days of work.

Try a three stages:
#1. 80 grit.
#2. 120 grit.
#3. 220 grit.
and see how it works for you.


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Yeah it did not do much to the aluminum! But it was the coursest I had on hand, and originally I thought just evening up the JB Weld would be enough. I'll pick up some 80-220 at Home Depot ... I had a giant pile of sandpaper at one point, I'm not sure what happened to all of it ... I probably used it all cleaning up my subframe last year.:cool:

OK, I stopped into a machine shop today and they evened it up for me. I think it's as flat as it's going to get. I'm going to take it to the DIY car wash tomorrow to make sure all the shavings are sprayed out of the housing, then install it and hope for the best ... :o

Well ... the good news is there's no longer visable coolant leaking out of the junction from tstat housing to block, when I pump it up with the pressure tester. At first it did a tiny bit so I tightened up the bolts and it stopped. So obviously the re-surfacing helped!:o The bad news is, it still loses pressure, but really slowly, and I can't even hear where the air is escaping, or see coolant dribbling. I'm gonna let it all dry off and get a better look at it tomorrow. Considering the last few times, I'm willing to call this progress ... :cool:

Carpet under dash isn't wet?

Sixto
87 300D

I had that thought at about 3 a.m. last night ... was just about to go look. I didn't think to check last night!:cool:

... it's still the tstat housing.:( I can see a tiny stream slowly appear underneath it (different spot than before), and can hear a faint sound of air escaping. I pumped it to 9 psi and in a half-hour the needle dropped about 2 mm, if that, so it's a tiny leak. There's an awful lot of coolant all down the block, though, that doesn't look like it's come from the housing. What a mess.
I tried tightening the bolts a little more but I don't want to overtorque them (still have not been able to find specs). I guess since it's such a tiny leak, I should try it one more time, with water pump gasket sealant. I did not use it this round.
How do I turn such small projects into epic sagas ... :confused:.

.... annnnnd it's leaking from somewhere else too. Big puddle forms on the ridge of the block under the water pump pipe, coming from somewhere other than the tstat housing. I'll have to completely remove the stinking AC compressor and bracket now (I only had to move it slightly to the side before) ... pretty much lost my patience for this ...