i have to change out my condenser and dryer on my 70 factory ac. the fittings where the dryer meets the condenser is stripped, good thing is that i have a new of both. i need to know how much oil to add, ive read from 2 oz. to 4 oz. by the way it been converted to r134, sanden compressor and all hoses = r134. i dont want to under fill or overfill.

 

Dump the drier out and put back what you pour out and add about 2 oz.

That's what I do anyway.

Make sure you use the right refrig oil, Pag or Ester, retrofits most often use ester, while most OEM stuff is pag... (depends what was used in your conversion)

 

ill just add 2 oz. trying to get every drop of oil out of the dryer and condenser is next to impossible.

 

well luck me. come to find out from the wife the compressor is seized up. guess the last two years of it leaking at the dryer fitting has run the oil down to much. good thing i have a new compressor, dryer and condenser. guess ill be flushing the system out completely. wont need to know the oil amount, seeing as ill be putting 8 oz. of pag in the compressor. next time i see a leak i think ill take care of it. wondered what i was going to do with all my free time.

 

you want a little oil in a new dryer when you put the new compressor in too...so id not put all of it in one place....also make sure you turn the compressor over about 20 times or so by hand before you vacuum charge and turn it on....you dont want to hydro-lock the new compressor

 

good idea. well it should ba swapped out tomorrow. went up and picked up the flush, i have the kit, tank and hose that is. first time i used it was because i was told the compressor had oil in it, it was empty. i checked the second compressor and it had the right amount, learned the hard way to double check. kind of figured it wasnt doing any good for the system to be leaking.

 

Seeing as circumstances have changed and it really doesn't matter...I am going to answer this anyway...

Your not going to get every drop out, the rule of thumb is that about 2 oz will stay in the drier, thus you measure what comes out and add 2 oz...

But of course this all goes out the window when you have a leak that consumes your freon and the oil that travels with it. Usually a leak like this will show up as oil on a hose, tube, compressor, or other component.

When this happens there are other variables, but for the original post, the generally accepted answer is to dump the drier, and add a like amount + about 2 oz, although I will have to be less than that precise/confined with many of my oil guesstimates.

 

thats what i ended up doing, well o added 2.5oz. i dont think a little extra oil, if i did that, is going to hurt anything. better to have to much than not enough. guess to much and it might cool as good but to little and could have a compressor fail. anyway it up and running, sounds perfect and blows cold. well see this afternoon when it gets to 100 degrees.

 

A little to "quite a bit" too much oil isn't going to hurt, way too much oil will bust a drier internally (so I have been told) spreading thousands of little silica B-Bs to the expansion valve/orifice... This takes more than twice the recommended oil for this to happen. A little extra oil is not going to hurt.

 

ill agree. friend of mine in prescott, 100 miles from me, is a certified mech, also in ac. when i asked him awhile back about changing out the condenser and dryer he said to add 2oz.. i figured with it leaking at the dryer connection to the condenser for a couple years now id go ahead and add 2&1/2 - 3oz. time will tell. the best way of doing it would of been take everything off, flush out the hoses and evaporator, drain the compressor, then put in 8oz. like a complete new system.