I have read in searching that it is a good ideal to get the ac system flushed and to get the oil out and put new (different) oil in. Does it matter if this is done after I put the new accumulator and orfice tube on? Or should it be done first? thanks.

That's a loaded question. Are you converting to a different freon? You do not have to Flush the A/C just to flush the A/C, like its Trans Fluid. Usually its done when a compressor fails or retro fitting.

OneBadZ4U

Here is the scoop: system currently doesn't work and never has since I have had the car the last 4 years (kicks on and off though). Got a leak test and there are a couple leaks. Need new lines and possibly a new compressor (must have blown a seal as there is a streak if oil on the hood lining and the hose near the front end). Going to also replace the accumulator and orfice tube as suggested when getting things going again. I am also going to convert to Redtek (not sure if you guys have that in the US?) since the price of 134 has gone through the roof now too. NOt sure what is in there as far as oil quantity or if there is crud so I thought it would be good to conserve the system with new parts.

Flushing the A/C is a good idea. I can help you with the proper oil levels, but I'm not sure what oil goes with the freon you're talking about. What modle car do you have?

85 firebird 2.8

So can i go ahead and put the new parts on first and then get it flushed and then vacuumed at once or does flushing ideally have to be before new parts go on (ie. could things get caught in the new orfice tube?).

Flush the old parts your re-using first. Then add A/C oil to the parts using the proper amount of oil for each component. If you are reusing the compressor, don't flush it!!! Drain it of oil. Then install the new parts with new seals and have the system vaccumed and charged. I'll add oil specifications a little later today.

don't you need to flush all traces of the old oil out of the compressor though? Isn't mixing bad? A new compressor is likely going on but it will be a used one that still was using R12 with that oil (mineral?).

On a side note, you seem very experienced with AC systems so I will throw this question out to you (since no one has replied to my other thread) as it is holding me up getting another compressor. Do you know what the differences are in R4 compressors other than v-belt/serp or mounting location? I have 3 prospects so far and all have different model numbers than mine even though at least 2 of them are v-belt like and on the drivers side like mine. Am I stuck getting the exact model like mine or are they pretty much the same and I could swap my brackets and/or clutch??

thanks for all your help so far!

To the first part of your question. You don't want the flushing agents in your compressor, could damage seals or other crap inside. At the shot I work at, we drain the compressor the best it can be and go from there.

I don't have exact information on compressor useage and brackets. My experieance has shown, that the clutch can be swaped over for the R4 compressor. The ones I've come across seem to mount all the same. However, usually there is a differance between the way the manifold lines mount up and there could be a pressure switch in the compressor that you may or maynot need. So you need to be very careful when swaping compressors.

On oiling the system, double check with the freon your using what type oil to use. I used PAG oil when swapping to R134A on my '92. Looking at the chart, you need to drain the compressor oil and measure it. If it's more than one once add the same amount of the new oil to the compressor. If its one once or less, add two onces of new oil. Add 3 onces to the evaporator, add 1 once to the condensor and 3.5 onces to the accumulator.

Good Luck,
OneBadZ4U

ok thanks for the info. THe compressor is going to be the tricky part then.

As for flushing the condensor and evaporator, can you jst use that brake cleaner that does not leave residue? I read somewhere that you can use ac flush or mineral spirits etc and I think it mentioned brake cleaner. Just wondering the validity to that?

thanks.

I used brake cleaner on mine. Works fine, I used compressed air to blow everything out.

I guess it would be best to take the condesor and evaporator out of the car to flush?? Is it easy to get the evaporator out?

IT's pretty easy. I just removed the dual fans with the radiator hold down cover and tilted the radiator forward.

That is the condensor, what about the evaporator? I have never remove one of those. Is there a lot involved?

Pretty much the same. Two 10mm bolts hold the evap cover to the firewall. 7 or 8 &mm screws hold the cap to the case(in engine compartment). Disconnect accumulator & liquid line. Bamm, you're there. Just make sure you use the proper wrenches to disconnect the A/C line and accumulator.

ok cool, thanks. I guess i will wait until the lines come and I figure out the compressor deal so I can do it all at once and not have it opened for long.

One other question I just thought of.....what about o-rings. I do believe there are different types, correct? What is the best type to go with and do they typically come in full kits or do you buy them separately?

Would a new accumulator come with new o-rings?

Sometimes the o-rings come with the component. Usually if you buy a R134a retro fit kit it will have the seals you need. I realize your using some sort of other agent.

Good luck.
OneBadZ4U