Too much A/C oil...

i tired searching for solutions here, and through google for anything anywhere else on the net and came up short everywhere.....so here's my story and my delima...
1990 Loredo 4dr, 4.0L, AW4, 2wd
been fighting with the A/C and vacuum leaks for quite some time now....i've gone through through basically every part of the ac, replaced the condensor about 2 years ago, had the system retrofitted for 134a (got completely new compressor ties, not little screw on adaptors) after this the system was still not as cold as it should be... this past winter pulled the dash out to completely redo all the wiring, had been wondering if my evaporator was insainly clogged or leaky so i pulled it, cleaned it out and pressure checked it (all good..)tried to recharge the system then with the help of my dad who designs and test huge ac systems for commercial buildings, and after about the 3rd or 4th can we finally decided that was enough freon....it wasn't charging right for some reason so thats why we kept going. while driving that night i eneded up blowing the burst disk on the bottom of the dryer which resulted in coating the underside and passenger side of my jeep in oil. a very large amount of oil at that. sooo...dad said there must be a clog somewhere in the high pressure lines. so today i installed a new expansion valve and dryer. i had pressure on both lines that i took off the front side of the expansion valve which i thought to be quite odd seeing as i never recharged the system after it... "blew its load"....and how i got a discharge of BOTH lines...so i figured the valve was where the clog was. when i got to the dryer i took the bottom line off first...which of course had some pressure on it as well!!! the top line was empty though. all 3 of this lines that still had a charge had a LOT of oil that came out....
so i just cleaned everything up and put it all back together....put a vacuum on the system for about 30 minutes then proceeded to add refrigerant with the cans i picked up earlier. now, these cans i asked the guy at the store for, and these are what he grabbed for me....at a glance it all looked like the right thing....after about the 2nd can i began to get very supicious as to why the compressor hadn't kicked on yet, and why i wasn't getting barely any pressure reading on the high side.....thats when i noticed the cans were NOT refrigerant......yea...thats right, the were OIL CHARGES....and knew right away that this was bad. especially with the amount of oil that appeared to already be in the system.
so i wipped out the trusty FSM to see what the recommended amount was and what to do in the amount of adding too much. book says 6oz. i put TWO 8.5oz cans in. PLUS what all was already in the system.
and all i can find about putting too much oil in is "don't do it". and that it will cause the air to not chill completely or properly. which explains why my air wasn't as cold as i thought it should be a while ago...
SOOO i went and picked up 3 cans of REFRIGERANT....and put them in the system...things went normal then, compressor kicked on after about 1/2 a can, and lines started getting cold or hot depending on which they were. after the 2nd can i went inside to feel the air.........not as cold as it should be......chilled, yes. but not as cold as some systems i've experienced as of late. added part of the 3rd can, low pressure gauge reads about 27-28 PSI. dad says to keep an eye on it tomorrow and see if it freezes up....


so here's my question to you guys. how to i get all this extra oil out?!? is there any decent way? is it even possible without completely disassembling the entire system and blowing it all out?

...thanks in advance!

Let me ask you something. You said that you put the system under a vaccuum. How did you do that? Do have access to a vaccuum pump? I'm assuming so since you stated that you dad does that for a living. What you may need to do is to use an actual a/c machine for r134a and evac and recharge the system that way. The a/c machines do pull out any excessive oil in the system. Then vaccuum the system for about 30 min (more to get the contaminents out of the system if there is any). Then recharge the system with about 20% LESS R134A than what the system takes with R12. DO NOT PUT ANY OIL BACK IN THE SYSTEM. Something else you need to look at is the type of oil that you put in. It should be PAG oil or Ester oil. If its POE oil, you have the wrong oil and may need to drain the oil out of the compressor. I believe the compressor has a lable that tells you how much oil the system takes.
Here's another tid-bit for you. NEVER use compressed air to blow out an R134a system. Compressed air and R134 are HIGHLY volitile!!! Not to mention compressed air has moisture in it. Not a good thing in the a/c system.

You also mention the pressure on the low side but you never mention the high side pressure. Low side sounds normal for your temp. down there but I'm curious as to what the high side is.

Hope that gave you some help. I work on this crap all day long. At least on Semi's that is.
See ya............Mike

I thought POE is Ester Oil?

if the system has too much pressure on it the ac clutch will kick in and out at wrong times not allowing the compressor to work properly. if you get a guage from like auto zone make sure its in or under the green. if overcharged with refridgerent, your ac won't compress cold air.

yes, i have a vacuum pump. i suggested evacuating the system to my dad and he said that wouldn't get all the oil out, and that putting the system under a vacuum with the pump would be the same thing... that kinda made sense to me because i knew evacuating the system was just reclaiming the refrigerant already in the system which would require putting it into a vacuum. he said the pump we have does the same thing except it doesn't dump back into a tank.
BUT...he works on residential and commercial building ac systems....not automotive and claims that they are different....so yea...

Ester oil was the 2 bottles i put in.....no clue what was in there before....

high side gauge read 150psi

thanks guys =D

KinesthesiaDrums said:

yes, i have a vacuum pump. i suggested evacuating the system to my dad and he said that wouldn't get all the oil out, and that putting the system under a vacuum with the pump would be the same thing... that kinda made sense to me because i knew evacuating the system was just reclaiming the refrigerant already in the system which would require putting it into a vacuum. he said the pump we have does the same thing except it doesn't dump back into a tank.
BUT...he works on residential and commercial building ac systems....not automotive and claims that they are different....so yea...

Ester oil was the 2 bottles i put in.....no clue what was in there before....

high side gauge read 150psi

thanks guys =D

Click to expand...

They are definately different. The automotive machines do pull oil from the system.They do not put the system under a vaccuum on the recycle (or evacuation) mode. All they do in evac mode is drain the system and oil, seporate the oil and put the R134a into a storage container. Once you make the repairs (usually) then you have to put the system under a vaccuum to remove any moisture that may have gotten in from the ambient air and also to recharge the system. Like I said, I work on this stuff all day long as a heavy truck technician. You're right on one fact though, you will never get all the oil out of the system. You can get most of it out of the lines though. The only other way to get the remainder of the oil is to pull the compressor off and drain it. Then put back in the recommended amount. I would try the automotive machine first and see where that puts you.
The high pressure sounds a little low. It should be around 175-200.
Also remember, when you recharge it with R134a put in about 20% less.
See ya...........Mike

alrighty, i'll try and get to somewhere with one of those machines, i appreciate your help!!