I have repaired and replaced about everything on this car. Living in Georgia, it is time to fix the AC or I will not be able to drive much between now and October. Heat Index is 100 today.

The Car: LT1 6 speed car with 120K miles on the AC system. The AC system is the only system that has not been through an R&R.

The Goal: Have a car that I can take a road trip in without worry that the AC clutch of compressor will lock up on the road.

AC History: Bought the car with about 112k on it about 5+ years ago. The car had many issues. One was the AC Clutch. The mechanic I hired to work on the car initially replaced the AC Clutch with a new clutch, supposedly. Later I realized this guy was ripping me off on repairs and I now doubt the AC clutch was a new unit. AC worked ok for awhile but seemd to place a huge drag when turned on.

Approximately 2 years ago I swapped out the AC Compressors because I thought mine had issues. (Another long story and I now know it was a mistake on my part.) The second shop did the swap and re-used the AC Clutch that I bought from the first mechanic. On the 20 mile drive home from the shop, the AC clutch appeared to lock up and melted the serpentine belt. I called the shop and they did not understand what had happened and wanted me to tow the car in. Disgusted with eveything I pushed the car into the garage and walked away from it for awhile.

Later I pulled the AC clutch apart to check for order of assembly. Externally all appeared OK with the clutch? I installed a new belt. It did not cool and the clutch acted like it wanted to lock up sporadically locking and releasing.

Now: I can drive the car but only if I unplug the power line leading to the AC clutch. With the power unplugged the AC clutch appears to give me no problems and does not show any sign of locking up. When the AC Clutch is plugged in it appears to drag and cycle irregularly and lock up some causing the belt to slip. I am a little baffled by this. Anyone have insight into this?

The Project: Rehab and Rebuild this AC system. Since this is the last system to fix before I really feel good about the car I am motived to get it going. I am considering buying a new Compressor, clutch, drier and orafice. If after doing my homework and if I feel confortable, I may end up doing much of the install myself.

Very Basic Steps in the process.

1. Have a shop discharge the system. (I am an AC newb, so I have this question: Once the R134a in evacuated fom the system can the car be driven or will the compressor lock up? I am assuming the shop only takes out the R134a and not the oil?

2.) Installing the new compressor etc. with proper nice new O-Rings. Add proper high quality specified oil to lubricate the compressor.

3.) Drive back to shop and have them pull a vaccum on the system and recharge.

4.) Drive home with the news parts in perfect working condition. I hope!

This is a start and feel free to jump in if you have first hand AC experience. Thanks!

Tools needed?:
R134a
Compressor Oil
AC Gauges
Vaccum pump (or shop assistance.)

 

Your clutch doesn't lock up, your compressor does. The clutch only engages the compressor. I'd replace the compressor with a new one that comes with a new clutch. Also replace the drier and the orifice tube. Have the system flushed, evacuated and recharged and you should be cool.

 

Clutch Plate needs an air gap of .020 inch between it and the Pulley, so if you're going to use what you have, get a shim kit to set it correctly. Make sure the surfaces are flat using a straight edge.

I'd get it leak checked - assuming it will run or if there's any gas in it. You want to stick an electronic leak detector in the vents or pull the Blower Module (electronic) or Resistor Pod (Manual) and wave it around the Evaporator to make sure it isn't leaking.

 

Once you remove the compressor you will lose all of the refrigerant anyway (Careful that shet can give you frostbite FAST!)

My suggestion? Do as above but do it yourself, it's not a hard job. I picked up an R134 AC manifold gauge kit with hoses AND vacuum pump for under 200 bux. You will also need a R134 can valve (10 bux)

All the instructions can be found on the web on how to do the job.

 

http://www.harborfreight.com/pack-of...ves-36118.html

 

I plan to do it myself. I have run out of money to donate to various locals repair shops. We must have a bad talent pool around here. No one can properly repair my car. I cannot afford to experiment with different shops anymore!

This is a a set of directions I found for charging the system

http://autoforums.carjunky.com/Autom...YSTEMS_P45460/



Always a good idea. Except I may need the fur lined model to handle the coolant.

 

The autoforums procedure is OK, excect it omits flushing ths system. This is an important step, especially if you had problems with the old compressor. They way to do it is get some AC system flush. Disconnect the various AC lines from the compressor, drier and remove the orifice tube. Pour the flush in and blow it out with compressed air. Put a rag on the other end and see if any bits of metal come out. If so keep flushing until there is no more.

 

I have been working on numerous other projects on this car. Frankly I had forgotten what the "symptoms" were with the AC. So, I just went out to the garage and started the car and plugged in the electical connector to the AC clutch and then got into the car. I turned on the AC on and it blew somewhat cold. Everything seemed fine for a few seconds.

Next the car started stumbling at idle. Something seemed to be bogging it down? I increased the RPM's into the 2000-2500 range. When I the rpm's got above 2000 rpm's I got a very noticable vibration through the car. Ragged bad bearing kind of a vibration.

Vibration at 2000+ rpm's when this is plugged in...


The vibration is not existent when the AC clutch is unplugged.



I definately have a bad compressor. Although it is not leaking at the front seal.

The clutch is good but the bearings in the compressor are totally shot is my guess?

The way I understand it is that AC compressor does not function unless the clutch cycles on and that is why I feel no vibration when it is unplugged?

What do you guys think??


Decisions, decisons usually means money or more money!

OPTION 1. Send original compressor (Not the one on the car now) off for a rebuild $181.00 shipped both ways. It does appears my clutch is OK.

Blendair
3367 ConFlans St.
Irving, TX 75061
Cost to rebuild AC Compressor $145.00+18.00 shipping. Joe quoted 6/28/2010 $24.00 for Condenser

OPTION 2 Buy a new AC compressor and Clutch $544.86
at http://www.ackits.com/

 

make arrangements with a the local paramedics; cardiac arrest is a known bypoduct of pricing LT specific compressors....and no they don't come with clutch. clutch is extra.

 

You can also disconnect the serpentine belt and let it idle and reve it a few ties to check for vibes

 

jakers,
based on your discription of the A/C operation, it Appears the compressor is trying to go into (Rotor lock) in doing so the internals begin to generate small particles, now if the problem is isolated to the bearings, most of the debri might be in the crankcase, but if the pump it-self is coming apart, particles leave the compressor through the high pressure side, and end up in the rest of the system.

Debri in the system is totally unacceptable for a new compressor install. You need to inspect the lines, condensor, and orfice tube for signs of debri. The condensor will trap a lot of stuff, but it's small internal tubes are next to impossible to though ally clean, and you can't get to them. Next in line is the orfice tube, this has a fine mesh screen and will also show signs of contamination, it is very easy to remove/replace with the proper tool. Following the orfice tube is the Evaporator, it should be just fine because it is protected by the orfice tube.

Bottom line...

Inspect the entire system for contamination.

Replace the pump, accumulator, and orfice tube.

you might consider http://www.autozone.com/autozone/par.../N-j1f01Z91sha if contamination is found.

Now after you disassemble, inspect and clean as necessary, and before re-assembly you may need to add compressor oil to the system. How much oil, and were to add it will depend on how far you go with the system.

This should be enough for starter's...

Good luck

 

if you pull it apart and find debris in the system you might as well replace the condenser. A lot of good shops do this because they know you can't get them clean once they are full of trash. Especially if you are spending the money for a new compressor.
In Georgia I would not go back with R134a in a vette. I don't think you will be satisfied with how cold it will get. I have HC in mine and it gets in the 30's with a never opened system with 25 yr old R4 compressor.

JS

 

JS

School me in what HC is?

 

Maybe he is making a referance to...Dichlorodifluoromethane (R-12), AKA, (CFC) ?

The factory (134) system works pretty good, when it's working correctly!

 

HC: Hydrocarbon Blend. Specifically outlawed in something like 19 States, most are considered flammable and therefore a poor substitute for R12 or R134, though seemingly used or accepted for use in Europe/Canada. I've heard rumors that the OEM's have experimented with them, but can't come up with a leakproof design for mobile a/c.