AC Q(s)

car is '99 Grand AM w/ 3.4 and 180K miles. Saturday the stock AC compressor started makinga gawd aweful racket (it was still blowing cold air) so I replaced it with a new one(not a rebuilt one). As I'm not reral quick on auto Ac I hired a guy to assisit. Before assembling everything we put in 8 oz's of PAC 150 refrigerant oil and then charged it with 28 oz's of refrigerant. It was blowing cold at the time so we deemed it good. Later on that eve it quit blowing cold. Checked for leaks and found known. So I refilled the system with refrigerant. Low side pressure was 30 psi and high side was 225 until the compressor kicked on. Then the high side went to 500 andvented pressure/refrigerant out and then dropped back down. It did this several times. I asked my dad why it would do this and he said we screwed up and put too much oil in the compressor. Manual says the compressor should get just two oz's of oil and the entire system should take about 9 oz's. So does it have too much oil now ad if so how can I get the oiil back out?

wat is that machine called I think it is Robin Air and it must be used to suck out everything from the system including a-134 and it will separate oil automatically.

here is calculation for you: lets assume you did not have any major leaks in the system so that 9.55 oz after 10 years decreased to 8 oz. Now you took the old compressor without measurieng how much oil was inside (the most it can fit is 4oz) but lets say it was around 2 oz so you had 6oz left in the system and you put 8oz that is 14 so you could have about 5-6oz of extra oil now. If you still have the old compressor measure the amount of oil in the crankcase.

The correct procedure is this:

when replacing compressor new one will not have any oil, so you have to remove the crankcase bolt from the old compressor and drain it in the measuring cup. And if less than 1 oz was drained from old compressor then you will have to add 2 oz to new compressor. If more than 1 oz was drained add the same amount of new oil to new compressor.

complete system takes 9.55 oz

I believe your old compressor only needed clutch gap adjustment

It is a recovery system and Robin Air is one company that makes the freon recovery systems.

Yeah that's way to much oil !

So after the systems empty 2 oz of oil and 6-7 oz of refrig.

I realy dislike the possition of the low pressure valve on these models, right by the exhaust manifold sucks! :(

And yes I have the burned knucles to prove it.

how much of the oil do you think I can get out of the system by pulling a vacuume on it and where would be the best place to tap into the system for the vac? Also is the orifice tube down in the wheel well near the dryer?

You might gave to do a complete flush of the system in order to get all the excess oil from the system.

And yes I have the burned knucles to prove it.
I hear ya ! :lol:
Even with Pro gauges you still get burnt. I always get my knuckles on the serp. belt, when its moving.


Yeah Jim, I'd try and pull out all you can with a recovery system, not just pulling a vacuum. If you think their's still oil in the system then I would only use 1 oz of oil in the compressor/system.
And yes the orifice tube screen(s) are in the pass fender in the dryer, and they should be replaced when the compressors replaced.

:2cents:

update: I opened up the system and drained about 1.5 oz of oil out, more came out when I vented the freon (book says it could lose as much as three oz's this way). Next I installed a new dryer. I then pulled the orifice screen. It was completly clogged with crud and metal shavings from the comp. I flushed the condenser and replaced the screen. Then added two cans of refridgerant and 2 ozs of oil. Its been two weeks and it has been fine. On 95 degree day it blew 40 degrees. Not as good a new but satisfactory none the less.