AC Oil volume upon replacement

CharlieS

SILVER Star
 
Joined
Feb 4, 2005
Messages
1,086
I'm about to replace my AC compressor, condenser and drier (along with my coolant radiator, hoses and tees). I have a new o-ring set and compressor oil, as well as gauges and R134A. I have the FSM.

My question is how much oil to put in the new AC system.

The FSM says 1.4-1.7oz go into the new condenser.

Does any go in the compressor (it is a new Denso)? The FSM doesn't say to add oil, but the instructions for the new compressor shows putting oil in the new one based on how much you removed from the old one.

I don't want to grenade the new compressor.

Any guidance would be greatly appreciated.


 

LBridges

SILVER Star
Joined
Oct 21, 2015
Messages
750
Location
Indialantic, FL
Most definitely do NOT start up a dry compressor. I would follow the instructions that came with the compressor, modifying them only if you can find a source for the total amount of system oil, keeping mind there will be some in the evaporator.
 

CharlieS

SILVER Star
 
Joined
Feb 4, 2005
Messages
1,086
Can you have too much oil?

The compressor I took out only had about a quarter ounce in it. The new one clearly has a bunch. Any harm if I just install it with the delivered oil quantity?
 

LBridges

SILVER Star
Joined
Oct 21, 2015
Messages
750
Location
Indialantic, FL
Yes there can be too much oil. But I'm not a good enough tech to know how much is too much. This website has a chart that shows total system oil capacity for the LX at 7.75 ounces of oil. It seems you are replacing just about everything except the evaporator(s) [plural for the rear ac unit that I am guessing you have?]. So one could assume 7.75oz minus what should be in the evaporator(s) and and condenser, and from that know the correct amount for the compressor. Never having replaced a Toyota AC compressor I don't know how it ships (might be enough to fill the whole system or might just be enough for the compressor - my guess would be the latter). The FSM for my 2000 LX suggests 1.4oz for each evaporator and 1.4oz for the condenser, which implies about 3.5 for the compressor (if my arithmetic can be trusted - you most definitely would need to triple check). Did you have a line blow out or similar? that would have resulted in a system oil loss.
 

CharlieS

SILVER Star
 
Joined
Feb 4, 2005
Messages
1,086
Yes, my rear AC lines blew out due to corrosion. I've capped them and am replacing the wear items in the AC system now.
 

LBridges

SILVER Star
Joined
Oct 21, 2015
Messages
750
Location
Indialantic, FL
OK, then I would press ahead with what's in the compressor and ignore the small amount in the old unit as a slow leak doesn't lose much oil but a line failure will spew a lot of oil along with losing virtually all the 134 refrigerant.
 
Top Bottom