A/C conversion

[montegut]

I plan to start the a/c conversation over to 134a this weekend. Will change compressor, dryer, orifice tube, o-rings, switch on the dryer. Anything I am missing? Any tips and tricks I should know? Thanks

[TopNotch]

You will need 8 ounces of Ester 100 oil. Put 4 in the dryer, and 4 in the compressor. If the compressor already has mineral oil in it, drain it first.
You will need a vacuum pump pull a vacuum on the system for 1/2 to 1 hour (depending on outside temperature) before refilling it .
If there is crud in the system (evidenced by grit on the old orifice tube), you should flush it .

[NoMad]

I would flush it either way. You have to have proof for warranty purposes on your compressor.

[Fierofool]

If you can find a heating and air supply store, get a bottle of Nylog Blue.  It's a sealer and lubricant that is compatible with all refrigerants.

It doesn't dry out.  Using compressor oil can cause corrosion where the seals are located.  A little bottle of Nylog Blue is only about 6 dollars and will last for eons. 

Every compressor I have bought came with instructions for what oil to use in the system.  My last one was compatible with R134a and used PAG 150 according to the leaflet.  It was a Four Seasons compressor. 

If you possibly can, save the pressure switches from your compressor.  The single wire switches aren't available any more and it seems to be a problem getting the system to operate properly when converting to the 2 wire switches. 

[montegut]

Thanks everyone. All very helpful. I had forgotten about the Nylog Blue. Just ordered some from Amazon for $9.00. Pushed back this one week so I have everything at hand.

[Raydar]

If you can find a heating and air supply store, get a bottle of Nylog Blue.  It's a sealer and lubricant that is compatible with all refrigerants.
...

Sealer?
I have a slow leak in my A/C system. It will hold a perfect vacuum for an entire weekend.
It was fully charged several weeks before the last RFTH. It now doesn't have enough charge to kick on the compressor.
As I said... a slooooowwwww leak.
I need to figure out something.

[Fierofool]

The Nylog Blue is for application on the seals and O-rings.  Not fit to inject into the system.  If anyone is planning to get into their system, I have a bottle to loan. 

[Raydar]

The Nylog Blue is for application on the seals and O-rings.  Not fit to inject into the system. 
...

Heh... Kind of like that whole "Lysol" thing. 
Thanks!

[GTRS Fiero]

Bleach?

[Fierofool]

Talking with RWDPLZ, he told me that using the compressor oil to lubricate seals and O-rings can cause corrosion in the area.  I don't remember where I got the recommendation for the Nylog Blue, but I believe it came from him.  It doesn't dry out and it remains pliable.

The bottle is about the size of a small pocket size bottle of hand sanitizer and cost around 6 or 7 dollars.  It looks pretty much like you blew your nose on the O-ring but I wouldn't recommend trying that if you don't have some Nylog. 

[TopNotch]

FYI: If your are converting a system from R12 to R134a, and don't completely remove ALL traces of the old mineral oil, you MUST use Ester oil in the system. PAG oil will not mix with mineral oil.
The oil you can't use to lubricate O-rings is PAG oil, because it is hydrophilic. Ester oil is OK, and in fact, Nylog Blue is an extra thick Ester oil.

[Roger]

I followed Charlie's recommendation on the Nylog Blue when I did my conversion and it worked great!
I did much later, develop a leak that I found to be coming from the receiver-drier input side. I had the folks at Sims Radiator check that out when I had them install a new water pump and t-stat and they found that 1/2 of the gasket was AWOL. They replaced it and used Nylog Blue, recharged the system and I can now keep meat frozen again.

[tiretread]

This is timely.  I'll be working on my A/C within the next 2 weeks. I'll be sure to pop back in when I'm ready to start my conversion.