Chevy air compressor pump

[JD4020]

I need to replace the air compressor pump on my Chevy Cheyene. I was told I just need to buy one and can switch it out on my own in 30 min. I want to make sure that when I unscrew the fittings, I wont spray freeon or anything all over, I was told by the mechanic who told me I could do it, that I will need to bring it in and have the air charged, is air the only thing that would leak? And I need to loosen the belt using the alternator, how is this done?

If I can loosen the belt and be sure I wont spray freeon, I can do the whole thing myself.

 

[JD4020]

Ok, I have the belt issue taken care of. And Im 99.9% sure I wont have a freeon prob. Any input?

 

[Kgmz]

Are you talking about the air conditioning compressor or the air pump for emissions?

It sounds like you are talking about the air conditioning compressor since you mentioned freon and having it charged.

If you are, yes you will lose the freon when you disconnect the hoses and yes the system will need to be put into a vaccum and then recharged with freon.

 

[JD4020]

Do I need to worry about the freon getting all over, or is it bad to come into contact with?

 

[polaris]

I'm guessing its the emissions air pump.

 

[celticcrusader]

if your working on air conditioner pump the answer is YES andYES

 

[JD4020]

Every thing is done. Everything also went ok. Im back in business.

 

[irwin]

I need to replace the air compressor pump on my Chevy Cheyene. ~snip~ I was told by the mechanic who told me I could do it, that I will need to bring it in and have the air charged, is air the only thing that would leak? ~snip~
If I can loosen the belt and be sure I wont spray freeon, I can do the whole thing myself.

Well? was it the emission air pump or the a/c compressor?

 

[JD4020]

Well? was it the emission air pump or the a/c compressor?

Sorry, ac.

 

[jughead]

must not have been any refrigerant in it or it would have made a mess. much less the danger of freezing pinkys.

 

[JD4020]

must not have been any refrigerant in it or it would have made a mess. much less the danger of freezing pinkys.

I brought it in to two mechanics before doing anything, and they said not to worry about that, when I did it, like they said, just a little PSSSSSSSSSSSSSSST noise.

 

[Freightrain]

Must have been pretty empty if it only hissed lightly. With 2+ lbs of freon it should have blow'd out for some time. As long as it's not in your face, you'll be okay. Just that Greenpeace might come knock'n on your door if they see you. "Global warming" and all that.

 

[JD4020]

Well it wasnt a loud HUGE HISS, but it did hiss for some time. We backed away and watched. Is it possible to refill it on my own? My uncle said I could buy a can to.

 

[Kgmz]

Is it possible to refill it on my own? My uncle said I could buy a can to.

Not without any problems after you fill it.

First you need a vacuum pump to pump all the air and moisture out of it.

Why? Because the moisture in the air will freeze at the valves, orifices and block the flow of the freon and then it won't work until it thaws out. and then the cycle starts again. Also the air in the system if charged with proper amount of freon will probably kick the compressor off because of high head pressure.

I just won't really work right, effectively, or cool efficiently if it is not done right.

 

[Freightrain]

From my experience...the vacuum pump is usually just for testing the system(for leaks). If it will hold a vacuum, then it will hold pressure.

Buy the kit at your local autoparts store. It usually comes with fittings, gauge, oil and Freon. It will usually take 2-3 cans of freon to get it totally filled after it's been opened. Make sure to put the can of oil in as it lubricates the compressor.

For the most part, if you put in TOO much freon, that is when the moisture will freeze in the lines, thus not allowing the A/C to cool anymore. It will then have to thaw before the freon will flow again. Using the gauge they supply, it should show the proper pressure needed. Read the instructions as the ambient temperature is used in calculating A/C temp at vents. Most systems will only drop ambient air temperture a certain amount, so the hotter outside, the warmer the vent air will be(though cold, it will be warmer then if it's 60 deg outside).

 

[EIB]

From my experience...the vacuum pump is usually just for testing the system(for leaks). If it will hold a vacuum, then it will hold pressure.

Not true. A vacuum pump is used to pull water out of the system. What happens is when a vacuum is pulled it lowers the boiling point of water. Thus turning it into a vapor and pulling it out of the system. The longer the pump is left on the better it is for a a/c system. Min. of 20 minutes.

As far as detecting leaks with a vaccum, if it is a big leak you will see it in a vacuum. If it is a small leak it needs to under pressure and use a leak detector. Better yet is to put dye in the system and use a uv light.

You can use a diy kit from a parts store, but it will not tell the condition of the system. You need a gauge set for that. To read high and low presures.

 

[celticcrusader]

Kgmz is right, without getting to technical do you understand what effects pressure and vacuum have on syst. and air and water??? if you do you won't just add freon from a parts store. you might get lucky and it might blow cold enough for you but you will not get 38deg. air out the vents.

 

[Kgmz]

From my experience...the vacuum pump is usually just for testing the system(for leaks). If it will hold a vacuum, then it will hold pressure.

It is used for checking a system for leaks, but its main purpose is the remove all the air and moisture from the system. And when a closed system is in a vacuum any water will boil and become vapor and is more readily removed


How do I know all this? Many years ago I was a commercial refrigeration technician/mechanic and silbrazer. We installed and maintained walk-in coolers/freezers, air-screens like you see the refrigerated food in the open cases at your local grocery store, ice machines cubed and flaked, etc., etc. And I still do this work for myself, as we own a convenience store and have owned several others through the years. And are planning on building 2 more in the next couple of years with one under way right now.

I own just about any refrigeration/HVAC tool you can think of. Several sets of gauges and analyzers, 2 vacuum pumps, a refrigerant recovery machine, a nitrogen test setup, a charging scale, a superheat/subcool meter, all the tools to do the copper piping from bending to flaring, swaging, and of course silbrazing and soft soldering any copper and brass from 1/8" to 6", etc., etc.

 

[bobcatmechanic]

you also want to be careful how much die and oil you put in the system as you can slug a pump with to much in there "slugging a pump is when to much liquid enters the pump area and as most know liquids are none compressible and will lock the pump up and then you just bought a couple hundred dollar pump same happens with to much freon in the system no where for the liquid to evaporate and it stays a liquid into the pump"

 

[Freightrain]

Thanks for the explanation. I was mis-informed, and didn't know the exact reasons why things are done. There is a difference between working and working well.