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Replacing ac compressor


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I am in the middle of replacing the ac compressor on my 02 bravada. the old compressor had a stud which the hose housing slipped onto and the had a nut that held it in place. All the new ones/ reman that the auto parts stores have, come with a cap which protects where the lines hook up and then a bolt holding that on. The problem is I cant get the old stud out and i am not sure if it is suppose to. But the bolt on the new one is just long enough to hold the temp protective cap and certainly isnt long enough to go into the compressor, allow for the hose housing to slide over and then the nut that holds the housing on.

 

So my question is does the stud come out and go into the new one? If so how? Second, do I need to just pour in oil before connecting the lines back up? I hadnt planned on recharging it asap since its getting cold but I dont want to damage it by not doing it correctly.

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yes you need to swap the stud. yes you need to add oil IF the compressor says it needs oil added. some come with oil some don't.

 

also i can recharge it, even though you don't think you need it since its getting cold when you turn your defroster on your compressor turns on to help clear the window.

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1. The "new" bolts are only meant to hold on those caps

2. You need to transfer the stud

3. You need to read the instructions, but typically the compressor does not come with oil in it, just assembly oil.

4. Remember there are several different types of PAG oil

5. General rule of thumb is to drain the old compressor, if you get more than 1 ounce out, add in what came out into the new one. If you get less than 1 ounce, add 1 ounce. Typically you would look on a service program to find out a factory specified amount when changing any A/C component.

 

Stud extraction.....

1 way is to PB blast it, put 2 nuts on it if possible and turn the lower nut to loosen. It will press against the top one and lock them together.

 

I would avoid using vise grips, it usually tears up the threads

 

Worse case, you need to go to the hardware store and get new studs, OR get a long enough bolt and use a bolt instead of a stud.

 

Hope that helps a little.

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The instructions are very vague. I ended up taking a bolt and threading it in then cutting off the head. I need to add oil but not sure how much. There was very little in the old one. Although it was a very nice shade of green. I have the new one in place and bolted down but I did not picked up oil yet. I hope they have some insight at the auto store in the morning. Theres 2 openings so does it matter which one the oil goes in?

 

Aj I was just going to use the fill cans from the auto store, but how much to recharge? I need to at least get it going by noon tomorrow because my wife has to have it. Am I safe as long as it has just the oil at least until I can get freon in it?

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The green color is just leak detection dye.

Yes, it already is filled for you.

Yes, it's ok to drive with that amount of oil with no freon. Think about it, if the oil is there to lubricate the inside of the compressor, if there is no freon the compressor will not run. The only thing that will be spinning is the pulley, not the internals of the compressor. The oil you put in does not lubricate the external pulley.

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Real quick, I got it all back together and went to refill with the cans and gauge from auto store. The gauge is all over the place. I hook it up and it read empty I had a few ounces in an old can but not near enough to fill an entire empty system. I push the dispensing trigger for a quick sec and it reads full, no way. I go get a new can and gauge and hook it up. The gauge bounces from empty to too much as the clutch engages. I have never seen one do this. Now how do I get an accurate reading?
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1) ICE32 is an "assembly lubricant" - you DO need to ad the correct amount and weight of PAG oil - if you look up the application here:

www.4s.com

Under "catalog", & "ecatalog" the oil listing will give you the weight and amount of oil and refrigerant charge. The wrong viscosity oil can cause compressor noise & damage. In this case PAG-46, 7.5 oz w/o rear A/C, 8.5 oz. with rear A/C. Refrigerant charge is 29 oz. w/o rear, 48 oz with. This assumes you flushed the system (more infor in #4) if not, adding oil will grossly overfill it with oil and you will have another bunch of potential problems (and the compressor will probably fail from contaminanation).

 

2) The system NEEDS to be vacuumed out before charging - air and moisture (humidity) are considered contaminants - they also take up room in the system. More tha 3% air in a system will cuase some compressors to knock.

 

3) You can charge from cans, but you need a touch type temp probe (no infrared) to check evaporator and condensor inlet and outlet temps as well as checking abient aire temp to the center duct temp. For you the primary check is to get the evaporator inlet (behind the orifice tube) to equal the evaporator outle temp. This will indicate full charge. The additional temps will check system performance

 

4) Why was the original compressor replaced? If it was an internal failure, the system should be flushed (it should be anyway as compressors wear they deposit aluminum "dust" in the oil, also, the old oil tends to accumulate in the evaporator - you install a new compressor without flushing and as soon as you fill the system w/refrigerant, you wash all that old, dirty oil into the compressor. Also, if it was a catastrophic failure, you may have enough debris in the system to partially plug the condensor.

 

5) I assume you also replaced the reciver/dryer and orifice tube?

 

Yea, if it has ICE32 it's one of my reman compressors - and yes, I do teach this stuff to techs every year.....

 

BTW - #1 cause of failure in orifice tube a/c systems - lack of lubrication from undercharging.

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Craig are you referencing my vehicle? Aj let me know when. It was replaced due to the front bearing coming apart. I have called 9 dealerships and asked countless people, all have stated that it has enough oil in it. My manual doesnt state how much oil , but does say it requires 1.9lbs of refrigerant. I did not replace anything but the compressor.
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Take it to ENR transmission by my old building at 820 w. broad street. Tell them I sent you over there, and pay the 100 bucks to evac and charge the ac.

Theres a place by me that will do it for $80. I need to decide if its worth replacing the accum/dryer and the orific(sp) tube first. Oh and make a determination on how much oil to put in it.

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I know where my mistake was and how I did it. I guess now I need to know how I fix it. The total capacity includes oil trapped in other parts of the system. Since I was ignorant going into the repair I wasnt aware that the compressor holds a certain amount of the total capacity and the best way to determine how much this is would have been to remove the oil from the compressor and swap it over to the new one minus the 1.5oz included in the new one. I spilled alot of it out during removal and this was my error. Since there wasnt an internal fault, I am taking a chance of not replacing the accum and tube in the hopes that I get lucky and no damage is caused to the new pump. I think now I need to make a guesstimate on what the amount of oil is that the old compressor held(not the entire system) and pray. I guess then I vacuum the system and fill with refrigerant.

 

I know at this point the best thing to do is replace the accum, tube, flush the system completely and start all over with the correct amount of oil for the total capacity of the system but thats all out of my scope of know-how.

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DO NOT get the stuff w/Sealer in it, period! The sealant can/will harden up all over the system and trash most if not all of the components. (it also voids all warranties on replacement parts)

 

As to "bad" 134a, this was primarily in 30# Cylinders. They were being imported and found to have a lot of air and/or water besides the refrigerant in the cylinder.

 

I have not heard of any problems with the individual cans.

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