i'm preparing to change my evaporator and since it is a huge task i want to make sure i have everything straight before i do it. I have wrapped my head around everything except one thing, where do i add the oil? most of the stuff i have read about this say to add the oil to the evaporator, but i have also read that you add it to the compressor. the FSM just says to add the oil to the system. I'm pretty sure adding it right into the evaporator is the right thing to do.
can anyone that has done this repair give me a little help?
thanks

 

When replacing the evaperator you really should change the filter drier also.
Just add 4 oz of oil to the new drier.

 

my compressor went bad last summer and i had that, the orifice and the accumulator replaced. the system stayed cold for about 2 weeks. there are only 2 components that aren't new and there no leaks under the hood so that makes me think that the evaporator is bad.
so when i change the evaporator do i pour the oil right into it or some where else?

 

You can add the oil to pretty much anywhere in the system.
When you replaced the other parts did you add oil then?
If so you might not need to add to much more. To much oil can be as bad as to little. Most refrigerant leaks I come across are the compressor or the hose connections. I hate to see you replace that evap for nothing.
Can you see any oily dirt buildup on the hose connections? Thats a good indication of a leak.

 

The FSM also states a specific amount of oil. The system should be flushed, the compressor removed and drained and the correct amount of oil added back. We added 1/2 of the oil to the compressor and the other 1/2 to the dryer.

 

i had a shop do the first repair, so i would think that they added oil.
the fsm says to add 2 ounces of oil when you change the evaporator.
maybe i'll get the system flushed instead and just let the shop add the oil

 

Most new A/C components come with very detailed instruction and will list the amount of oil that is required when installing the new part. Remember to vacuum down the system to 30hg to boil out any moisture and to pull air out of the systyem before recharging with refridgerant.

 

When we did ours, there were no instructions with the new parts (accumulator/dryer, hose manifold, liquid line/orifice tube and compressor. The new compressor said "no oil" add per vehicle specs.

 

so i changed out the evaporator and added the oil per the fsm, got it evacuated and filled and it's back to normal.

the mechanic told me that the electronic fan should stay on if the ac is running but mine will turn on shut off turn on shut off. i read about it in the fsm and it said that the fan will turn on when the pressure in the AC system reaches a certain point and stay on until it goes down to a certain point. the fan has done this ever since i bought the jeep 7 years ago so i think it is normal?

 

Is the compressor also cycling on/off?

 

i let it run for about 15min with the air on the highest setting. and the fan would run for about 10 sec then stop for 10 or 15 sec then run again. i heard the compressor clutch engage when i first started the air and i never heard it again. so i guess the compressor was running the whole time. after that i turned the air on and off a few times to see if the fan would start at the same time that the compressor did but it didn't.
the air works fine and the engine stays at the normal temp so i don't know if i should even worry about it.

 

dont think the newer xj fan runs all the time like the older ones do

 

Came across this while searching, might help you.

GL

 

ok so i guess my fan is functioning normally. thanks everyone for your help.