134 conversion refrigerant amount

[565bbchevy]

As far as I have read my 86' Regal with a 307 requires 52 oz of R12 and when converting to 134 only needs 80-85% of that which comes to a range from 41.60 oz to 44 20 oz
I was going to start with 80% and see how that works and go from there but I am curious what amount has worked for ones that have done this conversion.

 

[69hurstolds]

That's about right.

 

[69hurstolds]

Everything's been flushed and new accumulator, right? Need to make sure you don't have any mineral oil in there.

Using Ester or PAG oil...

Consider the newer barrier hoses and barrier o-rings, although you could just keep recharging.

Just things to consider when swapping over from R12. Unless all this has already been done, then never mind.

 

[565bbchevy]

Everything's been flushed and new accumulator, right? Need to make sure you don't have any mineral oil in there.

Using Ester or PAG oil...

Consider the newer barrier hoses and barrier o-rings, although you could just keep recharging.

Just things to consider when swapping over from R12. Unless all this has already been done, then never mind.

Everything in the system is new, using PAG 150 the compressor came with 3 oz of it installed if the oil amount is the same as R12 it calls for 8 oz total.

 

[DRIVEN]

I want to say I was closer to 70-75% but can't remember for sure. It's been 4 or 5 years now. I wrote it on my AC box but I'm not home right now to check for you. I'd probably start low and sneak up on it slowly. Watch the gauges and monitor vent temp.
When I replaced/converted mine I put some foam between my condensor and radiator at the ends. It seems to help, especially if you don't have an electric fan.

 

[Ribbedroof]

I've usually started at 80%, not over 85%...assuming OE capacity components (GM compressor, direct replacement condensor)

Recently did an aftermarket system on an A body Buick, the system manufacturer just wanted us to charge by hi/lo pressures.

 

[69hurstolds]

I recall specifically in a conversion chart I saw online from an A/C shop that 3.2 lbs of R12 would equate to 2.63 lbs of 134A in a conversion (about 82%). That's what I went by with the 84 H/O's conversion (but since switched back to R12). It worked well, but at idle it wasn't as cold. I'm thinking some of the design of the R12 system wasn't ideal with 134A which hindered efficiency at low rpm, but it worked well anything off idle. I've read it over about 100 times at various places that 80-85% worked. Obviously, you can start with 70 or 75 and work up to where you're good on the gages and air blows icy.

 

[lilbowtie]

Obviously, you can start with 70 or 75 and work up to where you're good on the gages and air blows icy.

Dito