Redrocket-98Z

OK, I was leaning over into engine compartment of my 98 Z28 a little while ago and revved her up a couple times. All of a sudden I hear, "BLAM" followed by some horrid grinding and clanging. At first I thought it was mains or conn rods coming out. Needless to say I freaked. I shut the engine off for a few minutes to look things over and think. A few minutes later I had my daughter start it up while I leaned into the engine area and listened. As soon as she started it the horrible rattle was still there (damn I had hoped it would fix itself). I had her turn the A/C off and low and behold the noise stopped. Ok, so not as bad as I had first feared but it is hot as hell here and need to get this rectified. I assume the compressor is bad.

I have turned wrenches for a long long time but am not certified for anything much less A/C work. I can get a compressor from Advance for ~$200 and swapping one part for another will not be an issue. I found an A/C compressor on EBay (don't laugh) and below are the installation instructions that were included in the auction:

1 - SYSTEM MUST BE THOROUGHLY FLUSHED, IF NOT THE NEW UNIT WILL BE DAMAGED.

2- MAKE SURE THAT YOUR MECHANIC CHECKS FOR DEBRIS/METAL SHAVINGS IN THE A/C SYSTEM. IF EITHER ARE PRESENT THEN YOUR CONDENSOR MUST BE REPLACED. IF THE CONDENSOR IS NOT REPLACED, THEN YOU WILL DAMAGE THE NEW COMPRESSOR.

3- BE SURE YOUR MECHANIC CHARGES THE SYSTEM PROPERLY. OVERCHARGING CAN RUIN THE SEALS AND CAUSE LEAKING

4- ALL UNITS ARE SHIPPED WITH APPROX. 4OZ. OF PAG OIL. MECHANIC MUST DUMP OUT THE PAG OIL IN THE UNIT AND MEASURE IT AND ADD MORE OR LESS PER THE SPECS FOR YOUR VEHICLE. PROPER AMOUNT OF OIL IS VERY CRITICAL TO MANY UNITS.

So here are the real questions:

1 - Is the compressor shot?
2 - How do you throughly flush the system?
3 - Is there a preferred method for checking for debris?
4 - Is the amount of PAG oil critical for this particular unit.

Thanks for any help you provide.

9000th01ss

iTrader: (10)

1.Purging any AC system is illegal, the refrigerant needs to be recovered with a recovery machine.
2. flush it and check
3. is the amount of oil in your engine critical or can you run 4 quarts short?
The oil charge is 9 ounces. Oh of PAG 150.

More important is pulling a vacuum on the system before adding refrigerant, how do you plan to do that?
You need a vacuum pump and manifold gauge set. If not you're wasting your time, money, parts.

slp--firehawk

Yea that's good advice, your probly not going to want to do this yourself if you had to ask thoes questions. If you have the hookup in the shop you should ask to get the vacuume left on over night, that's tlc and it makes a difference. I think wrenching the ac compressor on is like 5% of the total cost so you should probly just let someone you like and trust handle this job.

Redrocket-98Z

OUCH. Garage X gave me a $1,100.00 estimate. I was prepared to go 5 maybe 6 but for that money I will have to learn how to do it myself. Will post parts list/costs/proceedures and maybe some pics when I am done.

BTW I checked the parts prices from several places:

Compressor
Dealer - ~$850
Garage X- ~$425
Advanceauto - ~$250

More to follow.....

9000th01ss

iTrader: (10)

You can do it right and then take it to a shop and have them evacuate it (put it on a vacuum pump) and either fully charge it or just break the vacuum (put approx 10-50psi refrigerant in it)

This way you won't need a vacuum pump and you could use a cheap gauge and can tap. It takes exactly two full 12 oz cans so getting the right amount in with the small cans is fairly easy.

ta_06374

iTrader: (7)

I sell you my A/c pump I took off for $40 shipped.

orangefun

iTrader: (5)

also be sure the cooling fans are working correctly, because if the cooling fans are not on when the a/c is on it will raise the head pressure in the a/c system and blow the compressor, one of the two fan should turn on as soon as you turn the a/c on.

Redrocket-98Z

Does anyone know the proper ammount of oil to put into the compressor? One of my manuals says to dump the oil out of the old compressor and put that ammount into the new one. Is that correct? Seems odd to do it that way.

The computer at Advanceauto says it takes 9oz but when I dumped the old stuff out is was less that 5 oz.

9000th01ss

iTrader: (10)

Oil circulates with the refrigerant so every component of the system has oil in it.

#1 on your list says flush the entire system, did you do that?
You blew a compressor up, shouldn't you flush the debris from that out?

I'd flush the evap, cond, lines. Get a new accumulator, seals, orifice tube.

Now that you flushed all the **** out it has NO oil in it.

Now you can take 9 oz and divide it up. New compressors come with assembly oil so put very little in it and rotate it a few times.
Use a clean hose and funnel to pour some in the evaporator, and condenser. Put some in the accumulator and pour some in the rubber hose that connects to the accumulator and comes from the compressor.

What I do is a little different. I pour some in the rubber hose that goes to the comp. before i put it on the accumulator. Then I connect the vacuum pump to the suction side only (on the accumulator), disconnect the liquid line and let it suck into the condenser and liquid line.
This way theres no guess work and no doing it over.

Redrocket-98Z

I flushed the evaporator
I flushed the condensor
I flushed the hoses (condensor to evap, a/c pump to condensor, and accumulator to a/c pump)
I replaced the dryer/accumulator
I replaced the orifice tube
I replaced the compressor

I just measured the oil that came out of the old one. It was 1 oz.

The question is:

Is 9oz the correct amount to use?

9000th01ss

iTrader: (10)

Yes, just don't put it all in one place.
I already said that.

2001CamaroGuy

iTrader: (6)

wooooo, hold on.... this is any easy fix

- remove old compressor and install NEW compressor
- drive car to a shop that can recharge AC systems (most any repair shop)
- the shop will pull a vacuum on the system to check for leaks
- the shop will fill the system with fresh refrigerant
- good to go
- usual cost is $90-$100 for "labor" time, refrigerant, etc.


I can't count how many times I have had my AC system off/unhooked (some times for up to 6 months during fabrication/engine build/etc). Never a single bit of trouble. The keys are to:

- DO NOT let the system get water in it (keep the parts inside out of the weather)
- DO have the system evacuated (a vacuum pulled on it) to remove all the air and any moisture vapor

and saying it's illegal to "dump" the refrigerant (not have it recovered) is a big "what's your point"? It's also illegal to run without CATs but nobody thinks twice about that (unless you actually HAVE to get a tail pipe test). That law is for shops. Heck, who is to say the refrigerant didn't "get out" when the compressor broke...

VetteMan

People dump the refrigerant all the time.

9000th01ss

iTrader: (10)

Do me a favor and look at his post time, my post time, his edit time.
And also notice how his 1. 2. 3. 4. No longer matches my 1. 2. 3. he added the 4. after I posted.

#1 said something to the effect of how do I purge the system.
I don't make the law, I don't enforce the law. Yet if I said it's ok to vent the refrigerant I'd have a bunch of ****** on my *** about it.

integraxtc

iTrader: (11)

it's bad for the environment. don't let it out there, it's probably worse than cats.

I have cats, and intend to keep them.

My a/c doesn't work I'm just doing some research.