I think it's about time to start rebuilding the A/C on my 1985 L98 Coupe.

First thing I think I'll pick up is the compressor, but I had a few questions, I was hoping someone could answer.

1) I plan on purchasing this and then leaving it on the shelf until I get all the parts I need to rebuild the system. Do these things have a shelf life?

2) I'm looking at getting one of theses two (link 1, link 2). The only difference I can see is that one says "long shaft", and the other is "short shaft." Which do I need?

As a side note the only original items that I plan on leaving from the A/C system is the condensor and the evaporator. They are the only two items that (visually) look okay. I won't be able to tell for sure until I have a system that will at least hold a charge, however.

EDIT::: and more research reveals this, a reman'd unit from Autozone, and this, a new unit- also from Autozone.

 

1) Wait and buy everything at once, especially if you live in a high humidity area. They are not always sealed correctly, if you do a search you will see what I mean. Do not open your system on the car till you are ready, seals dry rot quickly and I believe you can ruin other parts as well.

2) Do not know the answer

Side note - SunCR is the one to ask about which parts are safe to leave on in a conversion from R12 to R134,

 

I guess your converting over to R134?
Make sure you flush the sytem.
Make sure you replace the Orifice tube.
Make sure you replace you accumulator.
Make sure you order SANTECH MT-2541 which fits all 1977 thru
1996 Corvette's. I bought mine thru a local AirCon dealer, but found out later that this is a regular stocked item at Autozone. UPC is 7-80250-02364-5
Make sure you don't buy the generic O-ring kit that Autozone sells, on my 93 non of them matched up.


Stay away from this kit... None of the O-ring sizes fit my 1993 AC system...


Buy this kit, all the O-rings are the right size....

 

be sure you thoughroly flush all of the lines, evaporator and condensor.
if there is any metal in the system it will eat the new compressor.
at work we use denatured alcohol and blow it through the systems with a pressureized canister

i plan to go with the new autozone a/c, to me it's worth it to know all parts are new

it's worth it to replace all the o-rings now while the system is open.

do everything at once too

 

My motivation for this project actually comes from tracking down a bearing noise in the front of my engine. I have it narrowed down to one of three pulleys- two of which have movement. The A/C Compressor is one of them.

I didn't plan on replacing the whole system yet, but I will have to eventually. I'm about 80% sure the A/C compressor is bad, both of the lines coming out of it are cracked along the rubber tubing, and one other line is cracked as well.

That's what I was afraid of and why I was asking...

I'm not really sure yet... but that would be a good idea, since it would be an all new system wouldn't it?

I plan on replacing all the lines (due to above reasons) and the, canister... whose name escapes me at the moment... because everywhere recommends that piece be changed with the compressor due to the reasons you listed.

Still no answer to long shaft Vs. short shaft though...
Any idea?

 

I don't know if it's long shaft or short shaft - I just go the AC Delco Site and look it up and I've always found the best prices at The Last Detail. I do know that what you order from them comes properly sealed and with oil in it. If you were concerned about it, you could dump the oil when it arrives. Flush it by putting in it (4 ozs) of whatever you're going to use for a lubricant. Turn the shaft a dozen or so times in one direction and then the other. Dump it out and repeat. Then put 4 fresh ounces in it and using the schrader that's affixed to the manifold seal that it shipped with, suck all the air out of it with a vacuum pump. You could then probably put it on your bench for the next 5 years and not worry about it.

As to the o-rings, one of the photos above shows sealing washers. They ain't gonna work with your compressor unless the manifold is designed for them (and it's not unless the inlet and outlet are flat. If it's indented, you need o-rings for seals. The Last Detail sells an o-ring kit that will work with any gas that's out there. I can't remember if the AC Delco ships with them - often they do come with what's going to work.

The last compressor I bought from Autozone - a new Factory Aire brand - sang like a goosed canary the minute I cranked it up. That brand has a horrible reputation, but I thought I couldn't go wrong with new. They gave me another one and reimbursed me for the oil and gas, but nothing for my labor.

You need an Accumulator to go with that compressor or just go here: http://www.autoacforum.com/ - and click on the FAQ Section and read all the topics (or join the Board and ask the guys who do this for a living).

Before you tear it apart - take it to a shop and have it leak tested. That way you'll know for sure that the condensor and evaporator are good. A new compressor isn't going to make cold air if either are bad.

 

Just curious why you say these o-rings won't work?
The MT-2541 package says "May contain extra parts". Yes, it contain everything for 1977 thru 1996 Corvettes. He may not use the seals I used for my 93, but he will use the O-rings that supplied in the kit. Goto www.lenzdist.com if more info.
It works for the following cars:
Rapid Seal Repair Kit for the following:

BUICK
Roadmaster 96-91
Century 96-87
Regal 96-88

CHEVROLET
Corsica 96-87
Lumina 96-90
Impala SS 96-94
Impala 96-94
Corvette 96-77
Celebrity 90-87
Cavalier 94-92
Caprice 96-94
Beretta 96-87
Camaro 97-92

OLDSMOBILE
Ciera 96-87
Cutlass Supreme 97-88
ninety Eight (8Cyl) 91-87

PONTIAC
Firebird 97-92
Grand Prix 96-88
Sunbird 94-92
6000 91-8705-97


Stock No: MT2541

 

What I thought I said was that the sealing washers (arrows in the photos) may not work - that was a design change addressed by a GM Bulletin that came along with the switch to R134. Some remans for the old R12 systems include the manifold that works with these washers - some don't, but most of the AC Delco units I've seen come with whatever it needs so that it hooks up properly. Use the wrong stuff and it's all going to leak out, so it's nice when it's all in the package.

 

Sorry for misunderstanding you. I personnally think you the guru on AC systems and just wanted to know why you said what "I thought" you said.
So, just to satisfy my own curiousity, you are saying this kit "will" work on all 77-96 as the vendor states. The seals I was pointing to are for 93's (and maybe other), but aren't the ones for the older models (but the rings for the older model are still in the kit).
Correct? P.S. I really enjoy reading your responses. You have given me a lot of knowledge... Thank-you

 

Thanks - it is confusing - GM (and all of the others) switched to a sealing washer at the Compressor for a better seal with R134. The Suppliers (AC Delco) then started offering Remans that would work with these washers, regardless of Year, usually appearing in the Catalog with a label that says the compressor is meant for R134 (and the only difference is how the lines seal up at the manifold). My experience at my Dealer, is that this is all they carry, so they stock sealing washers that work with them and if you ask for O-rings, they'll bring you the wrong parts. Finally took my old o-rings with me and I had my parts person scrounge around until she found me a couple (in fact I think I bought a half dozen since they seem so hard to come by).

 

Be sure to change the pressure switch at the Evaporator core. R12 & R134a systems have different pressures. The part number from Auto Zone is MT0207 for a 1991 Corvette. Things may be different for your model.

 

Thanks for all the input guys... I decided I'm going to switch over to R134a when I start replacing things.

I want to do it right, so this will take a ton of research on my behalf. I only want to have this done intime for next summer, which is why I asked about shelf life.

In any case: I now know the order I want to do things in, and what all I need. Thanks for all the info and part details. I'll probably end up getting everything at the local NAPA, when I do finally pull the trigger on this repair.

 

Unless someone swapped out the OEM switch, it's adjustable and there's no need for a new one if it's working. When you get around to doing this, repost and I or someone else can give you the details.

 

my system works fine except that it leaks out the R-12. So I am going to get the O-rings, replace them then convert the system to R-134. From some of the reading I've been doing it shouldn't be that hard of a project. The only question I have is about the 2 sealing washers, do I use those or do I use O rings?

 

It depends on the compressor - they're not interchangeable. If you're sure that what you have is original (no one mistakenly used the washers in lieu of the o-rings), stick with what's there now. New or Reman usually comes with what works. Any doubt - post a pic.

 

PS - O-rings are color coded to gas - Black R12; Blue is either; Green is R134. Sealing washers are always black. Most recommend that o-rings be coated with mineral oil (R12) regardless of gas as it has a lower affinity for water. Water can be problem on the low side as moisture can wick it's way into the fitting and set up galvanic corrosion between the parts. That has nothing to do with the seal, but everything to do with whether or not you can get it apart again. I gave up on my main hose when I rebuilt mine - it was rust welded to the Accumulator - so much for mineral oil being a better bet on this one.

 

Are you sure the compressor is bad. These are pretty robust units and dont need replacing as long as they still pump the required preassure.
If the noise is coming from the pulley bearing you can get a new clutck/pulley to replace the one that is making the nois at a fraction of the cost of a new compressor.

 

The R4 compressor ('84 to '87) isn't that expensive to replace - New or as a Reman. The Nippondensor ('88 up) is about twice as much, but easier to rebuild if it has a leaking shaft seal (which is what a lot of the Nippos seem to do). Here's the link I posted earlier this week to a guy doing the Nippo on his Porsche (it's also used on Lexus, Infiniti and couple of the other "better" cars and they always seem to spurt from the shaft seal): http://www.pelicanparts.com/techarti...so_rebuild.htm

Clutch Assemblys usually run a $150 - shaft seal kits $50 - I've seen Reman R4's for $250.

I'd would be concerned about cracked lines - not so much that they let all the juice out - but because they're getting hard to find. I'm pretty sure the high side from the condensor to the Evaporator isn't available for any Year. Main hose - Accumulator to the compressor and then out to the Condensor is available for the Nippos, don't know about the R4.

 

I found the cracked lines I need, most of the parts places have them, and they run about $100 - give or take (THIS is the line I need- yes I know it's ecklers, I just used them as an example. I'll probably get it from TLD-corvette).

NAPA has reman'd compressers for about $150 (see the link in my first post).