AC repair

My local shop told my my compressor was bad - that I needed to change that, the accumulator, and orifice tube.

I would really like to do the work myself, but I have never attempted AC repairs to this extent. I don't want to get in over my head but I have access to manifold gauges, a vacuum pump, and all the refrigerant I need. I want to save money, but I really, really want to learn how this repair is done. I think I'm pretty mechanically inclined - have done just about anything on cars, but never got into AC systems (other than adding freon).

Will I need to change o-ring/seals? (I assume the 134 refrigerant is different from what was initially installed). And are there any help guides to follow step-by-step procedures for this type repair? I have always wanted to learn this type of repair, but don't know any knowledgeable repair people. I need procedures to evacuate the existing, replace parts, and fill. Heck, I'd probably pay somebody just to show me how to do it because I want to learn it, but I don't know anyone that fits that bill.

Any help would be appreciated. Thanks.

My local shop told my my compressor was bad - that I needed to change that, the accumulator, and orifice tube.

I would really like to do the work myself, but I have never attempted AC repairs to this extent. I don't want to get in over my head but I have access to manifold gauges, a vacuum pump, and all the refrigerant I need. I want to save money, but I really, really want to learn how this repair is done. I think I'm pretty mechanically inclined - have done just about anything on cars, but never got into AC systems (other than adding freon).

Will I need to change o-ring/seals? (I assume the 134 refrigerant is different from what was initially installed). And are there any help guides to follow step-by-step procedures for this type repair? I have always wanted to learn this type of repair, but don't know any knowledgeable repair people. I need procedures to evacuate the existing, replace parts, and fill. Heck, I'd probably pay somebody just to show me how to do it because I want to learn it, but I don't know anyone that fits that bill.

Any help would be appreciated. Thanks.
I would go with a brand new over rebuilt compresser.
A good repair manual would help you.
Lot of good help and parts to here.
http://www.autoacforum.com/

What year and engine? I cut my teeth on those A/C systems... What is the reason compressor is "bad" - does it leak, noisy, or inop? Did it trash the system? was there refrigerant in the system? If you are willing to learn, I can help...

The shop said simply is was leaking - said the compressor on the s10 was notorious for leaking because of an o-ring assembly in the middle of the unit. I did notice that there is leaking from a shrader valve (don't know if that's the entire leak or not).

This is a 2000 s10 w/ the 2.2 engine, not flex fuel. Shop said I was fortunte because it was caught in time - I assume that means it didn't disintegrate and foul up the system. There is some residual refrigerant I think, but very little. The shrader valve still is under pressure, but the AC doesn't cool. The shop suggested a flush, but I assume that's normal for a repair of this type.

I'm not looking at rebuilts. I want new for the comp., accumulator, etc. As I mentioned I would dearly love to learn how to do this type of work. My background is in pumps, valves, fittings, etc., but I have not touched AC to the extent of reworking a system like this. I'm inclined to go ahead and do it just for the benefit of learning how to do this. I don't want to make a mistake, but I'd probably risk that just to find out how this type of work is done.

brcidd

BTW, thanks for the offer. I may just take you up on that if you're willing to invest time in an AC neophyte.

Do you know if the 2000 came with 134 refrigerant or not? If it did then I'm assuming I don't need to change out o-rings. But I assume new o-rings would not be a bad idea either.

Yes 134a was begat in model year '94 for most all S-bodies- there were a few box style still on R-12 till end of model yr though.

That compressor for your truck is an expensive V-7 (variable stroke) - they are the toughest to rebuild- so you should probably go with the new one- I've done a few but would rather do a V-5, or an R-4, or an HT-6 (six cylinder engine application).. They list for over $500 as I recall- but shop around....

Should I be leary of sources that are supplying a new comp., accumulator, and orifice for under $300? They claim they are new. I assume of course these are imports, but how can you determine a good comp. from bad when purchasing?

Should I be leary of sources that are supplying a new comp., accumulator, and orifice for under $300? They claim they are new. I assume of course these are imports, but how can you determine a good comp. from bad when purchasing?

Yes and no. :grinno::rofl:

What brand are you looking at?

Check ackits.com and compare what they have.

I found this site:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trkparms=algo%3DLVI%26its%3DI%26otn%3D2&item=310136419781&category=33543&viewitem=

Seems very legit as far as I can tell. I am a big ebayer, but I try to research my choices as much as possible before buying. I think the 1 year warranty, which doesn't require proof of "professional" installation, leads me to think it may be a reliable unit. I've never been burned yet on ebay, but that's not to say it couldn't happen.

I checked out ackits.com. Turns out I've been to that site in the past. They have a good reputation from what I understand. But I did notice the compressor was Chinese. So I'm not sure that I would get an inferior product from the ebay source(s) I've seen. Sounds like ackits stands behind their products also.

I checked out ackits.com. Turns out I've been to that site in the past. They have a good reputation from what I understand. But I did notice the compressor was Chinese. So I'm not sure that I would get an inferior product from the ebay source(s) I've seen. Sounds like ackits stands behind their products also.

Yes ACkits.com has good stuff and stand behind it.

A lot of stuff is Chinese made anymore.
Good or bad I can not say.

And proper installation also is very importain.

Make sure you flush system if it has anything in it.
Proper pump out and correct charge and oil to.
Good Luck which ever way you go.

Looks like the biggest obstacle might be the flushing. The compressor wasn't damaged - just leaking - but I'm under the impression that flushing is still very important, if not critical. But I don't have access to professional flushing equipment. Is this something the DIY installer can do with standard equipment? I know there has to be a flushing agent of some sort (although that's a little confusing as to what type), but I don't have access to nitrogen and other things that are probably used by pro's.

I'm also a little confused as to when to flush. Do I keep the system intact as much as possible before flushing, or do I remove the comp., accumulator, and orifice before flushing? Since these items aren't supposed to be flushed, I assume they can be removed, then the other parts flushed individually (condenser, evaporator, hoses). Before reinstallation of the new parts.

I always look at orfice tube and screen.
If any dirt or trash there system need flushed.
You can not flush reciever dryer or compressor.
On a flush get a flush agent or flush kit.
Unplug lines in and out of evaporator and condenser and flush good also flush out you lines.
Again ACKits.com should have flush kits.
After flushing you will need to add the correct AC oil and correct amount.

Some compresers come with oil charge in them and some are dry.

Drain new compressor and measure oil that came out.

Then add the correct amount to system.

Good Luck

I would not bother trying to flush the system out just because it leaked out its refrigerant charge. You risk causing more harm than it helps and actually GM doesn't recommend flushing. They recommend putting a filter on but I wouldnt' worry about that when all you have is a leak.

I think a good compressor choice would be the original OEM new. Sometimes you can find them on Ebay for less than some remanufactured off brands. The main thing is you need to replace the leaking compressor or any other leaking parts and replace the accumulator. Drain and measure the oil out of the old compressor and replace that amount with new oil in the new compressor. (Assuming the new compressor's empty). Generally a new accumualtor will need about 3 oz of oil. You can inspect the orifice tube for debris in the line exiting the condenser, but I'm betting you'll find that it's OK.

I think you said the service port valve was leaking? Sometimes you might have to replace the whole line if the service port isn't removable.

After you get it bolted back together. Pull a vacuum on the system and see that it pulls low and holds a vacuum for a period of time. Then put in a charge of refrigerant at the amount on the A/C service sticker.

This is just standard A/C repair and a good A/C book will explain most of it. To get any more specific than that we'd have to know what kind of A/C equipment you are using. If you are just using a manifold guage set with a vacuum pump and 12 oz refrigerant cans. What I do is hook the guage's low side up to the vehicles low side. hook the guage's high side to the vaccuum pump. Hook the charge hose to the refrigant can. this gives you good control of the recharging process and is safest. Say your system holds 1.75 lbs. That's 28 oz so if you put 2 12 oz cans in that will get you close enough without over filling it.

Manic
Thanks for the response. The issue of flushing is a little perplexing. I know GM doesn't recommend, but every aftermarket supplier seems to. In fact warranties are voided when flushing isn't done in most cases. I'm inclined to do without the flushing since the flushing seems to be the most tedious part of the job and I don't have the best equipment to do it. Since my compressor was only leaking, and not disintegrating, I'm inclined to just replace the comp, accumulator, and orifice. If there's any buildup on the orifice, then I'd probably do a flush to be safe.

I believe the schrader valve that's leaking has the removable core, in which case I'd just replace that. I have to look at it a little closer. It does appear to have a male fitting screwed into the service line if I remember correctly, so I'm not sure where the entire fitting would be purchased if the core cannot be removed. I haven't seen anyone advertising the entire fitting - just the cores.

Question: if I were to disassemble the components and replace with the new comp, acc, and orifice but don't evacuate and recharge right then, will that cause problems? In other words, if I replace the components and drive the vehicle for a few days before recharging, will I create problems (moisture, etc.?) I'm thinking with my time schedule I may have to split the repair in two parts.

Those compressors are notorious for leaks at the two case end "O" rings. If you get seven-ten years out of one of the earlier units, consider yourself very fortunate. Reportedly, the newer units (2003-up) have been redesigned to address that leak problem, and the new (not rebuilt) aftermarket units I've installed in the past few years have not come back for leakage. I think they might have wised up and installed quad rings instead of "O" rings in those locations, but I'm not sure.

It won't hurt to replace the components, drive it for a while with the AC clutch wire disconnected (it shouldn't run with no refrigerant charge anyway, but it's a sure thing if the clutch is disconnected), then evacuate and charge it later. Oil is critical, and you need to add the correct volume of PAG when installing the compressor, then manually turn the compressor to distribute the oil and clear the cylinders.

Definitely replace the orifice tube/screen unit and at the very least, remove and clean the accumulator, or just replace it.

Manic
Thanks for the response. The issue of flushing is a little perplexing. I know GM doesn't recommend, but every aftermarket supplier seems to. In fact warranties are voided when flushing isn't done in most cases. I'm inclined to do without the flushing since the flushing seems to be the most tedious part of the job and I don't have the best equipment to do it. Since my compressor was only leaking, and not disintegrating, I'm inclined to just replace the comp, accumulator, and orifice. If there's any buildup on the orifice, then I'd probably do a flush to be safe.

I believe the schrader valve that's leaking has the removable core, in which case I'd just replace that. I have to look at it a little closer. It does appear to have a male fitting screwed into the service line if I remember correctly, so I'm not sure where the entire fitting would be purchased if the core cannot be removed. I haven't seen anyone advertising the entire fitting - just the cores.

Question: if I were to disassemble the components and replace with the new comp, acc, and orifice but don't evacuate and recharge right then, will that cause problems? In other words, if I replace the components and drive the vehicle for a few days before recharging, will I create problems (moisture, etc.?) I'm thinking with my time schedule I may have to split the repair in two parts.

To keep system from drawing moisture.
Best to pump down and recharge as soon as you can after installing a new reciever/dryer.
After the sealing caps are removed from a dryer they tend to start drawing moisture.
That is one reason for a good vacuum pump down.

As Blue Bowtie says the correct amount and correct oil is very importain.
That is where a fush comes into play.
After a fush it is easy to get the correct amount of oil in it.
Good Luck

Manic
Thanks for the response. The issue of flushing is a little perplexing. I know GM doesn't recommend, but every aftermarket supplier seems to. In fact warranties are voided when flushing isn't done in most cases. I'm inclined to do without the flushing since the flushing seems to be the most tedious part of the job and I don't have the best equipment to do it. Since my compressor was only leaking, and not disintegrating, I'm inclined to just replace the comp, accumulator, and orifice. If there's any buildup on the orifice, then I'd probably do a flush to be safe.

Well you know how it is. The aftermarket suppliers probably reason that most people aren't going to flush the system or be able to prove they did, so it gets them out of honoring warranties even if it's their product that is to blame for a failure. The main thing is if you see no signs of debris, it's best to not flush it. And if you had debris you wouldn't be able to flush it out properly anyway yourself. You'd probaby need good flushing equipment and removing and cleaning/replacing condensor and other parts.

Question: if I were to disassemble the components and replace with the new comp, acc, and orifice but don't evacuate and recharge right then, will that cause problems? In other words, if I replace the components and drive the vehicle for a few days before recharging, will I create problems (moisture, etc.?) I'm thinking with my time schedule I may have to split the repair in two parts.

I agree with Blue Bowtie that it won't hurt to drive it for a few days. If you have it all sealed up good with a new accumulator, when you pull a good vacuum on and hold it for awhile it should get about as dry as it would've anyway.

I am preparing to replace the parts on my AC, but had a question specific to the S10. Does anyone know exactly where the orifice tube is located? There don't appear to be any obvious places.

Also what kind of CFM's are needed for good evacuation? I see lots of air operated pumps, but the CFM's are in the 4 range. Don't know if this is enough.

Thanks for your help once again.

OT is in evaporator inlet-at bottom of Evap- have to remove accumulator to properly access-

Thanks, br

That's no problem. I'm replacing the accumulator as part of the package.

Do you know what "good" pressures should be on the low and high sides?

Also, my accumulator is on the low side. Isn't the accumulator usually on the high side?

Good low side is around 28-32 lbs.

Remember evaporater out let tempt is close to low side tempt.

30 lbs = 30 degrees = cooling.
High side depends a lot on engine cooling and outside tempt.

150-250 is good high side range.
Good Luck