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Installing new AC compressor, does it need oil?

66K views 6 replies 4 participants last post by  CAR67 
#1 ·
Hi Folks,

I would really appreciate some pointers on installing a new compressor. I bought mine and got my new robinair gauges and vacuum pump. My questions are concerning the oil.

Does the compressor come with a full charge of oil or do you need to add some? If so how, what's the best way? A friend told me to turn the compressor with clutch side facing down and rotate it to lube the front seal. I guess a new compressor has to come with at least enough oil to lube the internals. I was planning on adding the amount stated on the sticker. Can you have too much oil?

Thanks in advance for your help.
 
#3 ·
Mikey,

This is what I don't get: why do I have to replace the dryer? I know a lot of people replace it, but when you put a new one in, you still have to have the system open to make connections, right? So what exactly does it gain you?

Thanks for the advise on the oil. I installed my compressor and put a vacuum on the system. I would have put the freon in but I'm missing the fitting for the can. Hopefully tomorrow i'll have a cool AC.
 
#5 ·
did your old compressor lock up or what happened? if it locked up you will need to flush the system to get the metal shavings out, because if you dont it will just wipe out your new one. I agree with mikey changing the receiever/dryer is a must when the system is open. it soakes up with moisture when the system is left open and also filters the freon. I would also replace the orface tube it also has a filter screen on it. it usually is very dirty anyways if it gets pluggen your ac wont work. hope this helps
 
#6 · (Edited)
like red said the dryer has a dessicant bag in it for moisture,leave it sealed and put it on last right before applying a vac. you will have to add oil (3-4 oz. in comp 4 in new acc./dryer search the internet and you should be able to find more exact amounts but those are pretty close you can have too much)to most look at the tag on comp. and put it clutch end down for a few minutes so the oil will lube the front shaft seal. also after putting on the comp. and hooking up the suction and discharge hose turn the comp. by hand to clear the oil out of it (10-15) full turns. get a new orfice tube also , flush system before installing parts use pag oil and pull vac. for 20-30 minutes.
 
#7 ·
Well fellas, I did not replace the dryer or the o-tube. I vacummed it last night got it to 30 mm of Hg, not sure of units, but gauge was almost pegged. Checked it again this morning. Still had same reading. I installed about 2oz of oil on the low side by pressurized can with the engine not running. It was a 3oz can but i'm assuming the pressure equalized and that's all I was going to get in.

Then I added my 850 grams of R134. It is cooling now. Not sure what the temp is supposed to be at the vent. I got 54 deg F with my cheap multimeter and about 63 deg F with my analog thermometer, both readings at idle. That is with no recirc flap. I pulled it since it had broken off.

The initial problem I had was that the clutch would not stay engaged. It would try to kick in 3 times that just stay off. I direct wired the compressor and it would cool and work fine. For this reason, I chased other things. I replaced the control head thinking it had to be a switch problem. That did not work. Then I changed the high pressure switch thinking it might be faulty, and that did not work. Previous to changing out these parts, I had taken the truck to an "AC specialist" he told me it had plenty of freon and that, that was not the issue.

So finally I replaced the compressor even though it did not make sense, same as 1Ton, Fire Medic, and Nav Man, all here on this forum. And that did the trick. Thanks guys, I appreciate your input. Next time, I will replace the dryer and orifice tube. You had good points on why these should be replaced. Right now, i'm out of work so, if this gets me by, then I will take it. Trying to conserve cash where I can. Thanks. :)

Alfonso.
 
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