To much oil in the A/C system, what now?

Billysgoat

Billysgoat

The ANTI-BLING!
Joined
Apr 21, 2006
Messages
10,694
Start of this year I noticed the A/C wasn't cooling very well, so I charged it up and started leak checking, found that a service port was leaking so I replaced the lines and dryer/filter. When I did this I shot a can of oil charge in first, followed by 134 till correct pressures were reached. I noticed that it would not really cool well until the engine had gotten above 1500 rpm or so, and basically acted like it was a bit low on 134. It still worked fairly good, so I just ignored it and didn't think to much about it.

About a month ago I had the joy of hearing something let go in the system and the A/C quit cooling again, knowing I had a heater core leak I figured it to be the evaporator giving up under pressure. This past weekend I got the dash out and replaced everything, pulled a vacuum on the system and let it sit overnight. The next morning it was still holding good numbers so I shot just 134 into the system until pressures were correct, added no oil.

The system acts like it did before, cools really good so long as the engine RPM's are up a bit, just OK at idle. I kept track of how much 134 went in and it was 1 full 12oz can, about 3/4 of another one. According to the sticker on the radiator support, the system should take 2lbs of gas (32oz) and I figure I put in about 20oz, so obviously something else is taking up room in there and the only thing I can think of is added oil.

What can I remove and drain with the best chance of getting some out? From the sounds when it is shut down, there is a decent bit trapped in the condenser so that is my first thought to get into. My plan is to yank it off, drain it out into a container and see how much I get out, sound reasonable?

I'm new to doing A/C work, the buddy I had who handled it for me before is gone, so I'm learning as I go LOL
 
I'm guessing you didn't evacuate the lines and just filled it up? If so the system is full of good old fashion air. You need to take it to a shop, have them put a vacuum on it, and then fill it up.
 
Sounds like he pulled a vacuum on the system and there weren't any leaks and was fully evacuated if it held vacuum over night. Definitely sounds undercharged if you only added 20oz of refrigerant to the system. I doubt you lost all of the oil out of the system when you had the first leak and definitely could have too much oil in the system if you added an entire can of oil to the system. I believe most of the oil charge cans contain more oil than is required.

I would pull the lines loose and flush the system with solvent and start from scratch. Generally a good idea anytime you have any major component failures and repairs. Add the proper oil and refrigerant charge and then check your pressures and temperatures against a pt chart
 
cummins cowboy said:
Sounds like he pulled a vacuum on the system and there weren't any leaks and was fully evacuated if it held vacuum over night. Definitely sounds undercharged if you only added 20oz of refrigerant to the system. I doubt you lost all of the oil out of the system when you had the first leak and definitely could have too much oil in the system if you added an entire can of oil to the system. I believe most of the oil charge cans contain more oil than is required.

I would pull the lines loose and flush the system with solvent and start from scratch. Generally a good idea anytime you have any major component failures and repairs. Add the proper oil and refrigerant charge and then check your pressures and temperatures against a pt chart
Click to expand...

I must have literally skipped over just that sentence.
 
Keep adding. Pressures go funky till about the end of the second can. After that, they start coming around through the fillin o the third can. I doubt you have too much oil in the system. You changed the drier, its an oil storage can. Try to drain it and see how much comes out. Also, an oil charge is only 2oz or so, you would start seeing severe issues with 10oz or more added. You also need to stick roughly one oz back in for every component replaced, except for compressor, which has its own spec.
 
If you really think its oil you can try taking the drier off and draining it. Its really hard to charge by pressure, you need to go by ambient temp.
 
To properly charge, you need to have the vehicle running and charge to the low side service port. There is no way to charge against static pressures without a heater of sorts. Applying heat to the can.
 
I did charge with it running, and pressures were set using ambient temp. Now that I have been using it for a few days I'll check it again just to be sure and see where they are at.
 
A/c systems work better under charged on oil but compressor longevity suffers. 2oz overcharged on oil will make the pressures run high and it to not cool right. If it won't take a full charge without over pressuring than its overcharged on oil. Remove accumulator and drain at least 1 oz
 
very good info here for someone learning about the system.

i recently purchased my own gauges and vacuum pump and it is WAY worth it to do it yourself. the longer you leave it on vacuum, the better.

i just loaned my equipment to a fellow forum member and he has the exact same problem. new equipment and too much oil!

also, i take the truck from high idle back to idle a few times to let the fan clutch do some work and pull different volumes across the coils. watch the pressure in both ways.
 
You must log in or register to reply here.
Back
Top