JPTL

After finding out I have a slow freon leak, & after adding some flourescent dye to the system, the A/C guy gave me two options:
1. Pay him to lift the car, remove the pans, and pinpoint the leaks with the dye light. Assuming leak(s) found at O-ring connections, pay him to remove the compressor, and replace the problematic O-rings as well as all others while he's under there. Paying an A/C guy who's at the pinnacle of his seasonal busyness to do non-A/C labor - $$$.
2. Lift the car and remove the pans myself, pinpoint the leaks with a dye light myself, remove the compressor, and replace all the o-rings myself.
Option 2 - waaaay cheaper, and I don't have to worry about an A/C guy jacking a 928 for the first time.
I'm opting for option 2.
So,
Step 1: Jack the car & remove the pans - no problem.
Step 2: Pick up a dye light. ! $300 & up! I couldn't find any place that rents them (I did notice that Dave A. mentioned renting one in an earlier A/C related post, but I couldn't find a rental anywhere).
Step 3: Find a 'cheap' UV/black light that will do the job. I found one! This thing is great, and for $13 delivered.
http://cgi.ebay.com/ws/eBayISAPI.dll...category=16085
It's actually a tiny handheld, battery operated flourescent light, and it works! Not as powerful as the $700, but it does work.
I found flourescent deposits around the Hi/Lo inputs to the compressor, so,
Step 4: remove the compressor.
I looked at Nichols site for step-by-step compressor removal instructions. Didn't find one. It looks kinda straight forward, but I'd like to have a step-by-step to review before I crawl under there (admittedly, I haven't checked the manuals yet).
Any posts/links with the step-by-step, or is it so straight forward that instructions aren't really needed?

Thanks

Bill Ball

Keith Widom has documented this on an early car. Same basic idea on a later car.

http://groups.msn.com/socal928/proce...65894495668693

You may have to "sign-up" with the SOCAL group's site to view.

dr bob

I think you can read or reference the SoCal site without signing up. You only need that if you want to post a message or reply.


On the compressor R&R--

Make sure your hoses and fittings are not under tension when you put the compressor back in. Sounds easier than it is. The hoses get attached to the compressor while the compressor is laying under the engine. Compressor then gets rolled/lifted into place for bolt-up

Put something under the compressor to hold it up off the floor whaile you rest your arms between reainstall attempts. Don't let it hang from the hoses.

Be Sure to replace the o-rings at the fittings where the little adapter fittings screw on to the compressor housing. 2 Rings per fitting, 2 fittings.

Do Not leave the heat shield out of the assembly. It's a chore to get back in with it compared to without, but it was put there for a good reason. It protects the compressur and hoses from exhaust manifold heat.

Mark the position of the adjuster before you remove the adjuster or the compressor. Do the same on the air pump adjuster. The ribbed belt on the AC unit is a lot tighter than you might think, so adjusting it back to the old position may be a lot more reliable than tuning for a "F sharp below middle C" twang when you strum on it.

Drain the old oil from the compressor and flush it out with a few cycles of new oil before you reassemble. R-12 uses a mineral-oil, while R-134a conversions should use polyolester.

You can buy a blacklight bulb to go in your trouble light for finding massive leaks. Look at Home Depot in the specialty bulb section. They are not expensive.

okbarnett

I hope you dont think you have finished just yet. Most of these cars are leaking at every oring in the system. Please start tracing every line thru the car. And as long as you have the system apart, replace every oring. After that, check your evaporator. Front and rear. Thay may be leaking. And also the front seal on the compressor. That probibly has a fair leak too. But as general principal; You dont have to use a green or colored dye. If theres oil leaking out, then theres a leak.

SharkSkin

JP,

Kragen's has the light with the glasses that enhance the dye signature for rent. Back east they may be known as Checkers or Shucks. I only buy bits of hose, fluids, and other non-critical items from them though, even for my Dodge. But the can be a good resource for some items, like tool rentals.

JPTL

Thanks for the info. It will be helpful for sure.
okbarnett, I do plan on replacing every O-ring while I'm under there, I just figured that the dye light would help to indicate the problem areas. I haven't gotten the compressor out yet, but I'm seeing rectangular plate(s) where the lines go in to the compressor. Are there seals behind these plates?
(Using Keith Widom's picture for illustration.)

JPTL

Looking up at the compressor from below, I'm seeing a concentration of the leak around this area. I guess it could be dripping from a connection above, but it's covering this general area:

dr bob

As you can see, there are two socket capscrews holding each of those little manifold plates to the compressor. Under each of those plates there are two o-rings. They leak sometimes, as evidenced by the oil you see. Those little plates also flex under the strain of the hoses, so if the hoses go in and pull/push/twist in the compressor fittings, you risk a continuing leak even with the new o-rings. Hence the above instruction on not installing the hoses under tension.

You are on your way!

SharkSkin

Looks like the O-ring under that rectangular flange. Did you add the green or is that the dye?

[edit] looks like dr bob beat me to it... [/edit]

okbarnett

Yes there are orings under the top compressor caps. They are big ones. May have a hard time matching them. I got them with a compressor rebuild kit. You may be able to tell if thats leaking with ac oil or engine oil dripping down from valve cover. And you should probibly replace the bolts with allen hex head too.

dr bob

the ones in my '89 were not big, might be 14mm or so but I don't remember the exact size. My local auto AC guy gave them to me.

The bolts on the '89 were already allen socket capscrews. I replaced the wimpy ones that were in there with some new ones, since the originals were really soft and got chewed a bit during removal. I ended up using an impact screwdriver on them to get them out; might be a good way to go from the start, rather than half-chewing them while trying to get them off with just a socket adapter and a ratchet. Never-seize on the threads during installation will make removal easier next time.


HTH!

JPTL

Once again, great advice. It's always so helpful & a huge time saver to be prepared for any job...big or small with advice from those who have been there/done that. I could've seen myself removing all of the support/attaching hardware to the compressor, and it free-falling 4 or 5 inches - putting the equivalent of 5 years of stress on the hoses. Thanks for the heads-up, Dr bob.

Dave, I added that color to Keith Widom's picture to show the area where the dye was (it wasn't as bad/green as that, but it was there).