Dremel your nuts... why do anything else?
 

I have read countless threads on removing the old heat exchangers and finally did the deed last night. Like others, I soaked them with Kroil for a few days before. Then using a dremel, a flex shaft, and a carbide cutter (tile cutting bit from Roto-Zip). Wow, I can't imagine why you would go through the hassle and time of a torch. I am sure there are plenty of you that will sing the praises of heat, which I know from experience works. I no longer have access to a torch, and quite honestly would not have used it if I did. Less than a minute of grinding on each nut and then used a hammer and punch to spin and open it at the same time.

For the barrel nuts, which are known to be less troublesome, I used a impact gun on VERY low pressure. It has been my experience that the short, quick hammering is easier on bolts and does a better job of loosening things up. The first go around I held the allen bit in my hand and could keep it from spinning. One came off, the others just got more Kroil. The next round I bumped up the air pressure about 15# and they all came off. No breakages and all studs were left in the head.

So, if Island911 is even in Alabama, I owe him a beer!

Thanks for the timely message. I too am removing my heat exchangers to replace 4 oil return tubes. I've had no problem removing all the hex head nuts from the studs except for one of the two nuts on the lower part of the triangular heat exchanger flange where it bolts up to the crossover tube. I tried multiple coatings of PB Blaster and heat. Now the sholders of the nut are rounded and I guess I will have to cut it off. What specific type of Dremel blade should be used to remove the nut? I don't know what you mean by "tile cutting bit from Roto-Zip".

Both Dremel and Roto-Zip are brands of cutting bits (and tools) you can get at Lowes/Home Depot/etc. My dad has used both the Dremel and Rotozip, and in his opinion the Rotozip brand is better; longer lasting, better tip cutting, etc. The tile cutting bit is carbide and readily available.

Be sure to use some PB or WD40 for lube, unless you have cutting fluid. Play with the speed of the Dremel and you will find a speed that seems to cut better... the sweet spot. Mine was about 3 of 5 on an old 395 model.

Good luck.

Good info, will have to try the Roto next time.

Guys, please... WD-40 IS NOT A LUBRICANT! As its name says, its a "water displacement" agent. If you want to lubricate something, please get a lubricant!

Re: Dremel your nuts... why do anything else?
 

Thanks for the offer. :) I'm glad you posted, and that it all worked out well.

Joe, you're right that WD40 is not much of a lube, however, I can see where WD40 helps keep the cutter cool --which helps.

Your thread title makes me cringe :D

Yeah, sorry for the frightening mental image!

I suggested WD-40 only because most people have some around and it is better than nothing. Ideally something like Tap Magic is better choice, but not very common. I used Kroil, which is not that common either.

Oh, and I did want to mention some advice Island gave me offline; He suggested using 1/4" drive ratchets to limit the amount of torque you are able to apply, or tempted to apply. To further explain my impact gun experience, I first tried the barrel nuts by hand with a 3/8" ratchet and then with a T-handle allen wrench. Both made me uncomfortable with the amount of torque I was applying. I can only hypothesize that the torque applied by the impact gun was less than I had applied with the wrenches, but I really think it was less force... the hammering action is what works.

Now for the stinking thermostat oil line nut...

About those thermostat nuts...... I started the dreaded "fix my dented oil lines" and add a 28 row brass cooler to my '79 SC this past weekend. I may do a post on it with pics later, but I found something interesting when attempting to heat the nuts at the thermostat.

I soaked the connections for two days prior with PB blaster, then attempted to heat the nuts with oxy/acet to get them off. They were not budging with a long wrench and fearing damage to my thermostat aluminum threads, I gave up for the evening but I did soak them again with PB while still hot.

I really did not want to cut the oil cooler line nuts as I did not want to have to buy new lines. I was frustrated that evening!

The next day, just for the hell of it, I put a wrench on it and low and behold, the nut was freed up! The combination of a couple heat cycles FOLLOWED by more PB while hot, then SITTING OVERNIGHT, did it!

I strongly believe in "hot wrenching" all exhaust nuts to remove, however the thin walled aluminum thermostat, just does not lend itself to standard hot wrenching procedures. The combo of heat cycles and the PB sitting overnight did it. I have no galled threads whatsoever and these babies were corroded on there pretty good I assure you.

WD-40 is commonly used as a cutting fluid -- I'm not claiming it's the best. Look in Machinery's Handbook or in a machinist's textbook for a list of cutting fluids. You select them based on the material, the speed and the feed...

Hey, I drimmeled my nutz and now I have this urge to wear dresses and high heels....and go to the mall. Help.