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Compressor Replacement for DIY'er Pages: 12Last

jtupper on Thu August 13, 2009 11:28 PM User is offlineView users profile

Year: 2000
Make: Chevy
Model: Tahoe
Engine Size: 5.3
Refrigerant Type: R134a

I have the dreaded tensioner clanging noise and vibration. I have replaced the belt and tensioner (twice) but the problem persists. I even had to have my tranny cooling line replaced due to a leak from the tensioner pulley banging against it. Everything I have read says the comressor is on it's way out...something about slugging refrigerant. Is this something your typical DIY'er can do? I can turn a wrench with no problems, but I must admit, I know next to nothing about a/c systems and have no special tools for this purpose. Typically, anything that doesn't involve engine internals I will try to do myself when possible.

From what I have read, I need to replace the compressor, orifice tube, and the system needs to be purged. Initially I was thinking I could pick up a new compressor and install it, then have an a/c shop purge and recharge the system. Is that feasible?

Cussboy on Thu August 13, 2009 11:31 PM User is offline

Yes, but legally you must recover the refrigerant. You also need to add correct amount of oil to replace that contained in the compressor and accumulator. And if the orifice tube is dirty, you should backflush the lines and condenser with solvent.

jtupper on Thu August 13, 2009 11:56 PM User is offlineView users profile

If I start over with a new compressor, won't there be a predetermined amount of oil I will need to add? Should I replace the accumulator as well? I assume everything just bolts up, correct?

Cussboy on Fri August 14, 2009 9:55 AM User is offline

Since your system still contains refrigerant, it didn't allow outside air in. It's a gamble whether you keep existing accumulator, but it's your gamble. In your case I might personally keep existing one there. I replaced the manifold assembly on my '94 Sub in January (crimp leak) and didn't change out the accumulator.

"Is the compressor a bolt on?" Essentially, yes. Your new compressor may or may not contain the correct amount of oil; I'd drain its oil out into a measuring cup or cylinder to verify that, then add back that oil or correct amount, and turn the compressor drive over a few times by hand to get the oil distributed throughout the compressor. Use new O-rings, with a little Nylog or R-12-type mineral oil as a lubricant on them.

jtupper on Fri August 14, 2009 11:44 AM User is offlineView users profile

Thank you for your responses. I apologize for all of the remedial questions, but I really am a newbie when it comes to a/c systems. I just like to have a firm grasp of things before I dive in. I'm leaning toward replacing the accumulator. It's cheap and I would rather be safe than sorry and do it right the first time.

I'm still a little confused about the oil. Is there no predetermined amount that must be added to a new compressor? It seems that if I drain the old out, there will still be some left in there. Should I add the measured amount plus a little extra?

Also, I have seen so many terms...evacuating, vacuuming, purging and flushing. Are these all essentially the same thing? In other words, what, specifically, should I ask for when I take it to the a/c shop to make sure there is no contamination in the system before they charge it?

TRB on Fri August 14, 2009 11:50 AM User is offlineView users profile

While we will do our best to answer all questions posted. Might consider picking up the Mastercool Auto A/C Repair Manual. It's not a step by step for every vehicle! But it is an excellent reference for general ac repairs which can relate to most vehicles.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

jtupper on Fri August 14, 2009 4:55 PM User is offlineView users profile

After much reading, I think I have answered some of my own questions.

Once I open my system, air is going to get in so no sense in putting a vacuum on it after it's evacuated. Once the accumulator, compressor and OT are installed, I need to have an a/c shop flush the system, purge it and then recharge it with R-134a. Is that the general idea?

Edited: Fri August 14, 2009 at 5:02 PM by jtupper

Chick on Fri August 14, 2009 5:50 PM User is offlineView users profile

If you are going to flush, leave the accumulator off..That goes on last right before you pull your vacuum.. Do not flush thru driers, accumulators, compressors expansion devices..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

jtupper on Fri August 14, 2009 6:09 PM User is offlineView users profile

That will be difficult since I do not have the means to flush it myself. My plan is to have a shop do the flush and charge the system after I install everything. Shouldn't a reputable auto a/c shop have the means and know-how to perform a proper flush?

Chick on Fri August 14, 2009 6:48 PM User is offlineView users profile

They will have to remove the lines from the accumulator, compressor, O tube etc..you cannot flush thru them..period, so don't be afraid to ask questions,

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

Prospeeder on Fri August 14, 2009 9:51 PM User is offlineView users profile

I thought the compressor sluggin on those vehicles was from somthing completly unrelated to the compressor. i cant remember but there wasjust a thread on it.

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1990 Pontiac Turbo Grand Prix
1990 Pontiac 6000 LE V6
Both have R12 A/C

chris142 on Fri August 14, 2009 11:00 PM User is offline

That compressor is a tight fit. Once you get the bolts out then you must find the exact angle of the dangle to pull it out between the engine, frame and heater hoses. It only goes in and out 1 way.

jtupper on Sun August 16, 2009 1:54 PM User is offlineView users profile

I called a shop and they quoted me $180 to vacuum and recharge the sytem and another $50 to flush. That makes about $230. Does that sound about right?

Also, I never mentioned I have rear a/c. Does that make a difference?

knightgang on Sun August 16, 2009 4:16 PM User is offline

That is about what I paid 3 years ago when I had to have one flushed, vacced and recharged. However, different shops and different areas will vary in price.

jtupper on Tue August 18, 2009 12:47 AM User is offlineView users profile

Okay, it's time to start buying parts. On the website it does not show my engine size for the 2000. That was one of the years that GM produced the old and new body styles in the same year. I am pulling up parts for the '01 as it should be exactly the same.

There are several different compressors listed. Four are new and two are remans. Is there any other difference between these? There are also three different accumulators. How can I determine which compressor and accumulator I need. Finally, should I replace the expansion valve for the rear a/c?

Here is my preliminary shopping list:

compressor - (which one?)
accumulator - (which one?)
orifice tube
expansion valve
o-ring kit
Nylog
compressor oil - (PAG 46?)

jtupper on Tue August 18, 2009 3:43 PM User is offlineView users profile

I talked to the nice folks over at AMA this afternoon and they steered me in the right direction. I have to get home today and check out the old compressor one more time to be sure I'm ordering the right one. I plan to place my order either this evening or first thing tomorrow morning.+

The one thing I am still unsure about is whether or not I should replace the rear expansion valve. My system is still functional and has never been opened, but my rear air has never blown real cold, just cool. I have also read where that expansion valve is a huge PITA to change out. Any guidance here would be much appreciated. With that said, here is my parts list:

RT201B - Nylog (Blue) Gasket Thread Sealant for HFC Systems
CP3010 - 1989-2005 General Motors System O-ring Kit
CP3016 - 2005 - GM Prior Sealing Washer Assortment
20-21711-AM - New Compressor w/ Clutch
37-23546 - Accumulator/Drier
31-50006 - Black - White Orifice Tube
41-50062-8 - BVA Auto 100 Easter Glow (8 Ounce Bottle)

Am I missing anything?

TRB on Tue August 18, 2009 4:51 PM User is offlineView users profile

A lot depends on the nature of your failure. If you have debris I say replace the rear valve as the entire system needs flushing. I personally would add the 640282PL condenser to the list.

Read up on Hecat's flushing procedure for additional information. Articles are in the flushing forum of this site.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

jtupper on Tue August 18, 2009 5:19 PM User is offlineView users profile

Quote
Originally posted by: TRB
A lot depends on the nature of your failure. If you have debris I say replace the rear valve as the entire system needs flushing. I personally would add the 640282PL condenser to the list.



Read up on Hecat's flushing procedure for additional information. Articles are in the flushing forum of this site.

That's just it...it hasn't failed yet. I would think the system should still be in good shape. My plan was to have the condenser and evaporator back flushed. Do you think I am asking for trouble by not replacing the condenser as well?

TRB on Tue August 18, 2009 5:26 PM User is offlineView users profile

All depends on the condition of the oil. Issue with flushing a PF condenser is you have a good chance of leaving flushing agent in the condenser. Flushing agent left in the condenser equals a failed new compressor which is not a warranty issue but a installment issue.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

jtupper on Tue August 18, 2009 6:37 PM User is offlineView users profile

Ok, so replace condenser too. Basically, all that's left are the front and rear evaporators and hoses. Is a flush still required?

knightgang on Tue August 18, 2009 6:45 PM User is offline

Quote
Originally posted by: jtupper
Ok, so replace condenser too. Basically, all that's left are the front and rear evaporators and hoses. Is a flush still required?

Depends on what you find in the OT and TXV when they are pulled out and like Tim said the condition of the oil. If you have metal shavings and/or gunk buildup on OT and in front of the TXV, a flush will probably be a really good idea...

jtupper on Tue August 18, 2009 6:48 PM User is offlineView users profile

I guess the better question is would not flushing the evaporators and hoses void my warranty?

knightgang on Tue August 18, 2009 10:23 PM User is offline

I do not have a direct answer for this but can say that it will depend a great deal on how sticky your retailer would be and how well they would inspect a compressor being brought back under warranty.

Tim could probably tell you his policy, but it could change depending on the retailer.

GM Tech on Wed August 19, 2009 1:40 AM User is offline

Based on the new 2010 Camaro compresor set-up- I have determined that the next bouncing tensioner problem I encounter- I will opt for the "stretchy" belt method--- no tensioner is used- instead a belt that is rolled on is used-- I will try this method- instead of replacing the "just broke in" compressor.

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

jtupper on Wed August 19, 2009 10:17 AM User is offlineView users profile

Quote
Originally posted by: GM Tech
Based on the new 2010 Camaro compresor set-up- I have determined that the next bouncing tensioner problem I encounter- I will opt for the "stretchy" belt method--- no tensioner is used- instead a belt that is rolled on is used-- I will try this method- instead of replacing the "just broke in" compressor.
I've read about that over on the GM-Trucks forum. My uderstanding is that the bouncing tensioner is caused by the compressor being on it's way out, which is why I am opting for this expensive repair. Even if I were to use the stretchy belt as a fix (cheap), wouldn't I still be looking at a compressor replacement in the near future (expensive)?

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