SeanR

Also, do not use ever increasing pressure while trying to remove it. A quick snap on the ratchet is all you need. Quick and snappy like an impact gun uses. Using low pressure to high is going to round out the connector.

NoVector

Yeah... someday I need to work on this Escher metamorphosis from 911 to 928 again:

M. Requin

NoVector, I'll be more than pleased if you just stick to the avatars...

Otto Mechanic

Update #2 -

It may be a few more days before I can do something with this. The liquid nitrogen I ordered through Amazon got sent to me USPS and they don't deliver parcels to my address reliably so it's sitting at the post office for the weekend. I've also lost my 17mm crow's foot. I can probably locate a replacement wrench before Monday but don't think anyone sells liquid nitrogen over the counter. Truth is, the stuff I ordered isn't liquid nitrogen anyway, it's something called "hfo-1234ze refrigerant ". I can't find it at the local hardware store either. It's here:

So I'm delayed another week.

Otto Mechanic

PS: Looks like both my 17 and 19mm crow's foots (feet?) have disappeared. My guess is, wherever they are, they're together

Otto Mechanic

PPS: While I was looking for replacements, I found this little beauty:
Never had one of these so I feel better about "replacing" it, just in case I find the original (which I'm almost certain got moved to Paso Robles). Only 5 bucks delivered but I had to order some other stuff to get that deal...

19psi

If you look at the specs, that's not even close to liquid nitrogen. -60ºF makes it a pricey can of air duster. Liquid nitrogen is -320ºF.

Jim Devine

Is you air cond charged? If not consider removing the fuel cooler & doing the job in a vice. The big nuts on the cooler lines come loose fairly easily. Rembember to replace the "o" rings with new.

Otto Mechanic

Yes, I did figure that out .

Still, it was as cold as I could get without buying or leasing a dewar flask, they're a little on the pricey side for this project, so I'm giving it a try before I either try to take the cooler out (which will have similar problems since it's a brass cooler connected with steel lines also) or springing for the LN dewar at my (sort of) local welding supply store.

I received the cold spray from Amazon today at a steeply discounted price since I paid for 2 day shipping and they sent it USPS, who don't deliver parcels to my shop. Had to drive 16 miles to the post office to get it since it was "non returnable". Amazon gave me a $10 credit, which paid for the gas and time to pick it up.

I froze both nuts today then soaked them in 50/50 ATF+acetone again. Will try with the new crow foot when it arrives tomorrow.

Otto Mechanic

Matter of fact, it isn't, but how is that important? I don't see any connections between the A/C and the cooler?

I do appreciate Sean's tip about using a fast break rather than a slow turn of the nuts. I'll certainly pay attention to that when it comes time for the next attempt, though the nut in question (the one to be replaced with Greg's new line) is already pretty bunged up. As an aside, I've found an "impact" version of a crows foot I could hook up to an air wrench I already have, that might be a choice I try before attempting to remove the entire cooler and put it in a vice.

Jim Devine

The fuel return to the tank runs through the fuel cooler so that if the a/c is charged it gets cooled before going to the tank- diagram here- click on fuel/ exhaust at top
http://www.autoatlanta.com/porsche-p..._928_parts.php
center left pic , lower diagram

Otto Mechanic

Sorry, I don't see it. There looks to be several diagrams from the PET on that page but I can't see any that show drawings of an '85 fuel cooler?

This was the only one I thought might relate, was this it?

worf928

Probably best to link a picture that actually has the fuel cooler (#57) in it:

Otto Mechanic

So the line we're looking at is labeled #58? Sorry for the confusion, there were several drawings on the reference. I'd actually thought that line carried fuel just from looking at it from the outside.

Then the answer is yes, the A/C/ isn't charged at the moment, that's a less important item on my list. I honestly had no idea the A/C was involved with the fuel cooler. It would be nice if I had a day or two that I didn't learn something while working on this car.

Thanks. I suppose this means I shouldn't have any real problems removing the cooler since the A/C system isn't charged right now. I re-built the compressor about 4 years ago but haven't put more than maybe 20 hours on the car since and haven't used the A/C other than to test it after the re-build so it's leaked down again.

Otto Mechanic

PS: I was a little confused since that was the PET diagram I posted on this thread at #15. I sort of assumed I was looking for something new in Jim's post, when all I needed to see was the line marked #58 on that drawing coming off the compressor. Sort of an easter egg hunt without the egg part