AC Compressor Replacement

[luke1834]

Ive searched around and not been able to find much in the way of DIY instructions for replacing the AC Compressor, so I figured a request to bring all the info to one post would be helpful, at least to me!.
I took my '99 to a local Indp. shop complaining of engine "surging" and intermittent stalling at idle. They diagnosed a faulty AC compressor (kicked on/off repeatedly and quickly) and quoted $1100 to replace the compressor and drier. They locked out the compressor and Ive been driving it since January. I want to do the job myself to save $$, as the water pump died about a month ago to the tune of $907.
I have a second vehicle for a few weeks and want to give this a shot while I can. Where does the AC compressor job rank on the "weekend mechanic" scale? Any tips, instructions, pictures or other advice are appreciated.

[JFP in PA]

It ranks a "0" on the DIY scale unless you have specialized Freon capture equipment, an AC system vacuum pump, measuring equipment for the recharge oil, and a set of R134 gas gauges.

And just a side point, did the AC work correctly before it was disconnected? I am not overly convinced of this diagnostic outcome………………..

[luke1834]

The refrigerant was removed from the system by the indp. shop when they diagnosed the problem. This was how they "locked out" the compressor so I could drive it without worrying about the issue recurring.
My "plan" is to have the same indp. shop fill the system once I changed the compressor and drier. Is this unreasonable given the circumstances?
I definitely qualify as a part swapper, including the coolant tank and AOS as well as many other jobs on other vehicles...though I am also familiar with a saying regarding mice, men and plans...

As best I can remember, the AC worked great before the issue started. It was January, though I do not recall any noticable noises or symptoms of problems with the AC. The shop said they pressure tested the system and found no leaks.

[JFP in PA]

Originally Posted by luke1834

The refrigerant was removed from the system by the indp. shop when they diagnosed the problem. This was how they "locked out" the compressor so I could drive it without worrying about the issue recurring.
My "plan" is to have the same indp. shop fill the system once I changed the compressor and drier. Is this unreasonable given the circumstances?
I definitely qualify as a part swapper, including the coolant tank and AOS as well as many other jobs on other vehicles...though I am also familiar with a saying regarding mice, men and plans...

As best I can remember, the AC worked great before the issue started. It was January, though I do not recall any noticable noises or symptoms of problems with the AC. The shop said they pressure tested the system and found no leaks.

That being the case, I do not see why they vented the system, they could have totally stopped it by simply pulling a fuse that would have cut power to the compressor’s drive clutch, allowing it to freewheel.
I am not at all comfortable with scraping a functioning system. I’d have someone more knowledgeable look at it first.

[milliemax]

If you can, turn on the AC for a few minutes every time you start the car so the oil/freon lubes all the seals in the AC system. This keeps the seals wet and tight. DANGER.. try not respond to this.

[luke1834]

I took a look at my maintenance records and the comments from the shop on the diagnosis...the surging stopped when they manually cut off the AC while driving. I am confident enough in their abilities and honesty that I will either purchase the parts and do the job myself or allow them to do it.
Assuming the AC system has been evacuated of refrigerant, what issues could come up when replacing the compressor? Is there some great danger if air gets into the lines, even though Im having the system evacuated, recharged and oiled at a professional shop?
I looked at my automotive manual and laid hands on the compressor itself...doesnt look like a terrible job and, short of the aforementioned great danger of damaging my AC system by DIY, I want to takle it. $1100 quoted from shop...I can get a brand new Denso compressor and dryer for $500 total...
Thanks

[j.fro]

My car is strictly an autocross car, so last year I removed the AC compressor, and it was working fine. If you want it, PM me with an offer.
My car is a 2000 Box S

[luke1834]

I was able to replace the AC Compressor and Receiver/Dryer this weekend, with the help of a mechanically inclined friend. Its definitely possible to attempt on your own, but it helped (and saved time) having an extra set of eyes and hands around! I only lack a trip to my AC shop to get the system oiled and recharged. All told, about $500 for the new compressor and dryer/receiver from Pelican Parts and $115 for the AC service at my local shop...not bad considering the whole job was quoted at $1100!
I didnt have time to do a full picture/tutorial, but I will share some key points:
Be sure your system is properly evacuated before you begin this job...I had mine done at a professional shop.
ALLDATA online manuals are a cheap and easy way to get some additional info on a project...certainly helped on this one!
The power steering fluid reservior had to come off to get the last of the three compressor mounting bolts out of its guide far enough to release the compressor...Plus, it gives you a additional room/sight lines to work with.
The compressor slides in and out through the front engine access very easily. When re-installing, align the top bolt (under the power steering reservoir) first, so you can pivot the compressor to align the other bolts.
The refrigerant inlet/outlet pipes required an allen and more torque than I could put on a T handle. A socket wrench and extension makes the job easier. I used new bolts when re-installing, as the heads were slightly damaged during removal.
24mm socket required to loosen the serpentine belt...

Good luck to anyone in the future on this one!