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AC Compressor change out procedure


pp270
07-15-2009, 12:25 PM
Might someone be able to provide me with an AC Compressor change out procedure or post a link to one. If one had pictures that would be great. I have a 2000 GP GT. 3.8 engine.

tblake
07-15-2009, 07:36 PM
Its not too difficult, but if you are not familiar its probably best left to the pro's.

-evacuate the system (shop will have to do this)
-remove serpentine belt
-remove bolt securing AC lines to compressor
-remove compressor electrical connector
-remove 2 (or 3 maybe) bolts holding compressor to block
-slip compressor out the wheel well
-dump compressor oil out of compressor into a container (measure this amount)
-reverse instrustions to install new compressor (add the same amount of Pag Oil that came out the old one)
-bring car to shop, have 30inches of vacuum pulled for an hour and then recharged with proper amount of R134a.

pp270
07-16-2009, 07:22 AM
With some improvising I changed out the compressor. Does anyone know the R-134a capacity of a 2000 GP GT 3.8 in oz?

rkvons
07-16-2009, 12:19 PM
That info is usually printed out somewhere under the hood. Check the capacities section of the owner's manual.

doctorhrdware
07-16-2009, 04:13 PM
Before you can put the freon in you must have a vacuum pull it order to remove all the moisture from the system. Tblake stated this in his post above. If it is not done you can hurt the compressor. Plus the system will not cool properly.

tblake
07-16-2009, 04:14 PM
Improvizing? Like how? I hope you didnt let the freon go into the atmosphere.

CrazyHorst
07-16-2009, 07:36 PM
The R134A is "environmentally safe"...an untold number of vehicles lose part or the complete charge thru the compressor shaft seals, vehicle crashes which puncture the condensor, etc.

It cost $60 for my GTP to be evacuated and recharged. I changed the compressor, filter drier, orifice tube, condensor and the hose asms. It is icy now on Recirc.

R-n-R the compressor is much, much easier if you remove the coil pack bracket and the associated hardware. While not impossible, there are some bolts that are tricky to access.

tblake
07-16-2009, 08:58 PM
Thanks for clarifying crazyhorst, I was unsure what all had to be removed on the 3800, I've only had the pleasure of changing a compressor on a 3.4 V6 Chevy Mini-van, which I assumed is similar.

Also, Good observations dock. I missed where he said he added freon without a vacuum pulled.

CrazyHorst
07-16-2009, 11:59 PM
This is a post from 17k ago when I did this work. There is some info and a picture of the backside of the compressor there showing the bolts I was speaking of.

http://www.automotiveforums.com/vbulletin/t940644.html

doctorhrdware
07-17-2009, 02:10 AM
Crazyhorse, where did you get the honeycomb plate for the throttle body. There is an area that looks like it was punched out on mine.

CrazyHorst
07-17-2009, 08:58 AM
Doc, I purchased it from RockAuto....look in Fuel/Air and then under Throttle Body. It is called a "screen" although I refer to it as a flow-straightener. Just be gentle with it is my only advice, I was having some troubles getting the "pressfit" to work right and I ended up using a wide flat block of wood to help distribute the forces....I was worried my thumbs were going to fold or damage it. The wood worked perfectly, no damage.

pp270
07-17-2009, 09:19 AM
No freon has been added yet since the system still needs to be evaced. The shaft seel was the problem. Also the exterior bearing was almost seezed. It was definitly time for the change out. I did have to remove the coil pack to get access as suggested above. In total there are five bolts. Three in the front and two in the back. Oh also the one nut that holds on the AC lines. I also will be changing out the accumulator and orifice tube before evacing the system and recharging. For now I just have the compressor wire disconnected so it won't engage the clutch and run the system.

tblake
07-17-2009, 09:30 AM
Crazyhorse, where did you get the honeycomb plate for the throttle body. There is an area that looks like it was punched out on mine.

ZZPerformance sells them in their used section for $1.00. Which includes the screen and large snap ring.

tblake
07-17-2009, 09:31 AM
Nice work pp270! I'm glad you got the job done! However if you live in MN right now you'll need the heater today! A high of 60 degrees (for mid July) Grrrrrr!

doctorhrdware
07-17-2009, 12:22 PM
Remember Tim Global warming is in effect. BTW thanks for the heads up on the throttle body honeycomb plate. I will get that ordered. It is 72 degrees here today.

tblake
07-18-2009, 10:35 AM
Global Warming.. Pshhhh. I'm about ready to hack my cat converter off just to speed it up so we can get some decent weather in mid july again.

doctorhrdware
07-18-2009, 03:06 PM
Global Warming.. Pshhhh. I'm about ready to hack my cat converter off just to speed it up so we can get some decent weather in mid July again.

It is 62 degrees here today. This freaking weather is killing me. My lower back which I had the most surgeries is absolutely killing me. I was thinking about going to the farmer's just around the corner from my place, and I ended up blowing it off. There is always next Saturday. It is very dark here. Looks like it is going to rain here.

pp270
07-20-2009, 12:17 PM
Two more questions:

1. Where is the orifice tube located on a 2000 GT GP?

2. How do I by pass the low pressure switch so the compressor clutch will engage to rechage the system?

tblake
07-20-2009, 08:00 PM
I think it is located under the brake booster area. It may be easier to access if you remove the air intake duct.

I think the car should just take freon. Problem is you need to pull a vacuum on the system first or else you will have moisture in the system and it will litterally eat itself from inside out.

doctorhrdware
07-20-2009, 09:36 PM
Tim is right in order for the AC system to take a charge, you have to pull a vacuum on it first. Leave the vacuum on the system for approximately 45 minutes to 1 hour. Then what I do is to close the system off, with the vacuum still pulled down on the AC system. And I leave it that way over night just to make sure that there is no more leaks in the system. The reading that you got prior to closing the system you should get the same reading.

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