Heat Exchanger Barrel Nut Stripped - Help!

[SonomaPete]

I'm removing the heat exchangers on a 69 911E. I've been using the 8mm Allen 3/8 extension tool from Pelican Parts to remove the barrel nutes -- four came out like magic, but the final two were a bear, and I managed to strip the tool and (I'm guessing) the barrel nuts themselves. I'm going to go to a machine shop tomorrow and have the stripped tip of the tool cut off -- if the barrel nuts aren't too stripped, things might be OK.

But... what if the nuts are stripped? They're so inaccessible (it's the center and rear barrel nuts on one side), I don't know how I'll get them off, short of cutting away the heat exchanger with an acetylene torch. Any less catestrophic suggestions? (Engine is out of the car and on a stand...)

Any suggestions would be much appreciated...

--p

[Tim Walsh]

hmm... on mine I can see the nuts from the outside, but then I've got a post '75 exhaust system on there with standard nuts. Can you see them inbetween the HE's and the block?

[SonomaPete]

I can see the standard nuts from the outside, but the ones I'm having trouble with -- the barrel nuts accessible only via the holes that pass through the heat exchanger -- are visible but not reachable...

[VincentVega]

I went through this this year, every barrel nut was stripped on my car before I started. To get them off I cut off the heater boxes, heated the nuts and used vise grips to get them off. Of course the heat exchangers lost their heat, but they came off.

Best of luck!

[SonomaPete]

chris, how hard were the heat exchangers to cut off? Did you use an oxy-acetylene torch?

[VincentVega]

They were not fun at all. I used a combination of a air cutoff tool wit the the grinder attachment, an air chisel and channel locks. I think a torch would have been faster, but I dont have access to one. The real hassel was laying on my back getting sparks and metal pieces everywhere. If you have a cutting torch they should come right off.

[Kevin G]

I went through the same thing last year. I used a large sized regular screw driver( the tip being slightly bigger than the inner diameter of the barrel nut ), heated the barrel nut until cherry red, used a hammer to pound the screwdriver into the barrel nut, turned and it came off. I got this idea from someone else who also had this problem and did it this way. What ever you try good luck!

Kevin

[Gunter]

Heat is the answer! If you can apply it quickly right to the nut and then go in with the Allen socket. That socket needs to be sharp and new at the business end. Did you pre-soak with penetrating oil? The best heat would be with an acetylene torch (Small tip) Propane is second best because it tends to heat slower, thereby also warming up the stud and that is not wanted.

[jhelgesen]

Go check out sears, they have some new nut extractors that go on the end of a socket. I received a set for christmas this year and just got to try them out last night on some stuck engine tin screws. Just tap it in place then turn with a wrench. The design pulls the extractor onto the head or nut and out comes the fastener.

[Rot 911]

When you mean "stripped the barrel nuts" I assume you mean you rounded out the socket hole? If so get a torx socket slightly larger than the socket hole. Pound that sucker on with a hammer and see if you can the get the barrel nut off. If not, the cut off the heat exchangers (assuming you are installing new ones). I cut the old rusty ones off my 911 using a reciprocating saw with a bi-metal blade. Only took about 5 minutes!

[SonomaPete]

Thanks everyone for your advice. As it turns out, only the tool was stripped... this morning, I cut off the end, and with a "fresh" tip, was able to remove the barrel nuts without a problem. fwiw, the nuts themselves were not stripped at all... the tool must be a much softer metal.

[cary]

I'm glad the outcome was good.

I'm begining to think. That some of the best quality tools you should invest in are the hex/triple square drives. You can sure make a mess of a project when they round out.
Most of my tools are Craftsmen. But after replacing my 5 & 6mm numerous times ( CV joints ) I switched to Snap-On. They make the hex part replaceable. Which tells you they are a wear item.

But they are still much harder the the Craftsmen.

[mikedsilva]

Bumping this thread since I now have this bloody problem. I used the Pelican 8mm tool.. and tapped it into the nut before trying to undo it. At first it was very tough, then all of a sudden it started to turn so I thought it was undone.. turns out, it stripped the inside of the barrel nut.

I don't want to have to cut off the heat exchanger!

I also have the 10mm pelican tool.. sounds like I will be sacrificing some tools to see if I can get this bugger off. Wouldn't you know it, all the others came off fine.
Yes, I did use penetrating oil, but to no avail.

[island911]

This should help Duck food

Although, you may want to try getting a Torx drive, or slightly larger SAE allen up there first.

[mikedsilva]

thanks..
I was thinking to try and grind with the dremel first, to weaken the nut a lot, so when I jam the torx or whatever in there, it would come off a bit easier.. I will update later.

[DRACO A5OG]

You really need something like the Erwin nut extractor to bite that nut.



When I striped the inner triple square head bolt on my 190e, the extractor saved my rear.

A dremel trick would work too if you get it in there.

[john walker's workshop]

Are you heating red hot or trying it cold? You don't say which.

[juanbenae]

Originally Posted by DRACO A5OG

You really need something like the Erwin nut extractor to bite that nut.



.

god forbid a DIY'er would require the whole freakin kit!

you can get singles of an easy out bit that would work. get the back out bit to where it's starting to sink into the nut good, then remove it. heat to red hot as john is likely suggesting above, then reset the easy out bit and really push hard as you try to ratchet it out lefty loosy.... I would be reluctant to heat nut with the easy out bit already embedded. try to get to the loosening while still hot. a map torch should work, the gas in the yellow bottles if you don't have an oxy-acetylene set up.

what do you guys think of trying an impact in reverse after the easy out bit is fully engaged in the barrel nut? would the impact action help at all? of course you'd have to adapt the easy out to a 1/2" drive for the impact mating.

[DRACO A5OG]

OP, why not post a pic so we can see what you are dealing with?

[mikedsilva]

I think the most difficult part, is access.

The barrel nut is used because it is on the "inside" of the motor... and the only way to access it is using a very long 8mm hex key. I had to buy the expensive tool from Pelican, since I could not find anywhere local, that made one long enough.

I do have a small gas bottle but it is blue, not yellow.. not sure it will heat up enough. Perhaps I will try the carbide cutter, then heat, then sheer violence !