So I decided to change the whole a/c compressor.I just have some questions before I start because I've never done that before.At the same time I'm thinking to replace the A/C & Altern. belt and the power steerenig belt, also idler pulley.
So as far as I see the A/C compr. is mounted by 4 bolt and 2 for the a/c lines. I was thinking before to start to go somewhere to have the gas taken out and then have them put it back in.Otherwise if I take the 2 bolt for the lines the gas will go out right? Is that where the O-rings are?So If I take all thoose bolt out the A/C would be alble to come out and don't really need special tool for it right? After I have it out I'll just put the other one the same way back in. Is there anything I should know so far if I'm doing something wrong or something? Ok after I have the compresor back in do you use some special oil to put on the O-rings? I allready have the idler or tensioner.They told me from the store that there is no idler listed and that they have tensioner so I brougt the old one overe there to measure and they are the same diameter It's just a little wider a tiny bit.It wouldn't be a problem right? So how tight you need to tighten the bolt for the idler and then how do you loosen the power steering belt? After I have everything back in I heard that you need to put some oil in the sistem.How do you do that, before you charge the sistem? and where do you put the oil from ?Is there anything else I should do.I just wanna make shoure that I do everything the right way.Now there is nothing wrong with the air.It is blowing cold and I don't want to screw it up.

The car is Crysler Sebring '02 , V6 , 2.7 sedan

I'll appreciate any help

Thanks

 

I have to admit I'm a little hesitant to answer these questions. I mean, where do you start teaching someone how to fix an A/C system? I don't want to discourage you-- I'm a DIYer and so far I have successfully changed two compressors a condensor and a number of leaky o-rings. I did spend a good amount of time online and in the service manual reading up on proper procedures though.

First, and most important, do not open the A/C system until the refrigerant (some would say "freon", but not technically correct) has been completely removed. This means that a shop would use their machine to pull the refrigerant out and get the system into vacuum (negative pressure).

You've probably heard about how liquid nitrogen can freeze a hot dog in less than a second and then it will smash like glass, right? Well refrigerant is the same way. It exists as a liquid under pressure in the A/C system and if you open the system with any refrigerant in it, it will spray out in partially liquid form and instantly freeze any body parts it contacts (including your eyes.)

It is also possible that when the shop recovers (removes) the refrigerant from the system, some of it stays dissolved in the system's oil and some can remain in liquid form in the system. Professional recovery should get it all, but when you open up the system after that, you'll definately want to wear gloves and full-surround eye protection in case.

So now to answer your other questions-- there are either o-rings or other seals at the compressor connection. A new/rebuilt compressor will usually come with replacement seals and you should use them. Better yet, you could buy the A/C line disconnect tools (the plastic things made by OEM for about $10) and an o-ring kit for your car and replace all of the seals. It is also standard procedure to replace the receiver/drier whenever the system is open-- moisture, including the moisture in the air is the enemy of your system. The receiver/drier contains a material that absorbs a small amount of moisture and you want to refresh that any time the system is opened up.

On the topic of moisture, it is best to keep the system open for as little time as possible to avoid moisture getting into it-- also tape off or plug up any lines/connectors that are going to be left open for a while as you do the service. You can use the same oil as the system uses to lube the o-rings on installation. I think there's also a product called "nylog" that people say ensures a better seal.

That brings me to oil-- I'm pretty sure you'll use PAG-46 oil, but you should check your manual. You will need to know exactly how much oil the shop removed during the recovery process (their machine will separate it and measure it, so they should be able to tell you) and you will need to drain the old compressor and measure the oil that comes out of it. You then add these together-- that's the amount of new oil you have to add to the new compressor. First drain all of the shipping oil out of the new compressor and discard, then replace with the exact amount of new oil that you figured out (just pour it into the compressor intake.)

Your manual will tell you how much oil you need to add when you replace the receiver drier. Pour that amount into the new receiver drier before installation. After you get the whole system together, give the compressor a few turns in the correct direction with your hand (not just the pulley, but the compressor itself) to clear any oil that might otherwise damage the compressor on start up. Next, promptly take the car to a shop and have the evacuate the system and install a correct refrigerant charge.

FYI-- Don't try to just fill the system with refrigerant yourself unless you want to invest in a manifold gauge set and A/C vacuum pump. The system must be "evacuated" meaning they attach a vacuum pump and pull the system into deep vacuum for about 40 minutes-- this removes all air and most of the moisture from the system.

I hope this info is useful, but definately search around some more online and read your service manual about how to do this properly. I think Haynes has an A/C repair manual that may have some good info too, though I've never looked at it too closely.

 

Without the proper methods and tools, you shouldn't attempt the discharge/recharge of the system. You're setting yourself up for disappointment if you do. Poor A/C efficiency is the most likely result, and by the time you finish you'll have spent nearly as much as to have a professional do it.

Contact an auto refrigeration specialty shop and make arrangements with them so that you can have them do that part. In between, you can replace your own compressor and other parts.

CAUTION!!!!! Leave the electrical plug to the compressor detached after replacing it!!!!

If you run the compressor without oil, well, you can imagine the damage. And simply turning on your defroster will start it.

 

It sounds like you intend to have a shop do the recovery/recharge service. Although it's unlikely you'll want to get the equipment to do the recovery (I bought an older machine for about $200, but it can be hard to find a deal like that), you may want to get the equipment to do the recharge. You can get the manifold gauge set at harborfreight for about $35 and the vacuum pump for about $70, less when they are on sale. Although you'd likely break even on the cost of the recharge for this job, you will get to keep the tools for the next time you or a friend have A/C issues (which is pretty common.) You can even get a decent electronic refrigerant leak detector for about $40 on eBay. There's lots of money to be saved DIYing A/C stuff, even if you have to buy a few tools IMO, but you do have to take the procedures and risks of injury seriously. For me it was no big deal to learn what I needed to know, you'll have to judge your own abilities.

 

Thanks for the advice and the help.I'll probably take the car to the shop to take the refrigerant out and have them put it back in the system after that.
So I still didn't understand if you need special tools to disconnect the lines from the A/C compressor.I see that there is one bolt for each.Is that it?
Thanks

 

Correct. The lines are connected to the compressor with those bolted-on fittings. The lines to the expansion valve/evaporator are quick-connect lines requiring a special tool. You shouldn't need to disconnect them although most compressor manufacturers will issue a warranty only if you replace the expansion valve and receiver/dryer at the same time. Their thought is that disturbing the system can shake loose particles in the lines which will circulate until trapped either in the receiver/dryer or in the expansion valve.
Personally, I think that's overkill, and I have successfully replaced three different compressors (on three different vehicles) without changing an expansion valve. Ya pays yer money and ya takes yer chances.
Follow Rick's advice about measuring the oil and using the proper oil for your vehicle. I have a shop manual for 2001. In two different places, it says "Only the refrigerant lubricant approved for use with this vehicle (SP-15 PAG oil) should be used to service the system." and "The oil designated for this vehicle is ND 8 PAG (polyalkalene glycol)."
So for sure we know that PAG oil is required. There are different viscosities of oil available. To my knowledge, ony GM cars use the heavier viscosity.
Be sure to replace the o-rings where you disconnect the hoses from the compressor. Don't use plumbing o-rings from the hardware store. Get proper A/C system o-rings.

 

^^ good info. BTW-- the disconnect tools needed for the snap fittings (like the fittings at the condenser) are cheap-- only about $10 for a set of the plastic tools. If I were you, I'd take the oportunity to replace all of the o-rings and the receiver/drier since the system is open, but don't break the seal at the expansion valve. It's not necessary to replace the o-rings other than the ones at the compressor, but it's cheap insurance against a future leak.

 

Those tools also are useful on fuel filters and other fuel connections.
I own a set and it has saved me much grief.

 

Thanks guys

 

Just did this project this week...sort of. My sons 2001 300M A/C compressor went out, bought the parts,compressor, A/C receiver dryer, proper oil and valve. Talked with a shop to discharge the system and recharge after we install the compressor and parts. The shop said why don't you bring the parts and we install.....that's what we did. We are fairly competent mechanics but too much running around.

Total parts $315.00 and total labor $340.00.