FLushing fluid is like $11 a quart, mineral spirits is $3.50 a gallon from home depot. I used over two gallons recently flushing the system (again). You do the math !!
I understand that the DA6 compressor is not suitable for the 134 conversion due to the higher system pressure needed when running with 134. The HR6 (I think that's the number) is ok.
Flush everything 'cept accum and compressor which you should replace. Replace orrifice tube, options are standard one at $2 or a variable orifice tube, so called 'smart' orrifice (smart ass!!) at $26, expensive but it does work better with the 134. I had one in till I cooked the compressor again due to inadequate flushing.
Flush again, both ways if possible.
Replace the O rings at the joints with ones suitable for 134, the original ones are not really up to the job. O rings are usually supplied in conversion kits.
Change the hi/lo pressure fittings to 134 type fittings. You''ll need a special tool to get the high side schraeder valve out. got mine from advance autoiparts for $2.
Flush again (did I mention you need to flush it out really well!!!).
I used a flushing bottle. Fill the bottle, pressurize, insert nozzle into pipe, flush, repeat.
Blow (preferably) dry air through the system. Some people use nitrogen (nice if you have it).
Load system with oil, Use Ester which is compatible with any of the original mineral oil that may be left, PAG is not. It takes 8 oz of oil, put 4 in the accum and evap/condensor. Put rest in compressor and pipes.
you may want to charge the compressor with oil before you install it on the car is it is pretty much impossible to do one it is in place.
Connect pipes. The fitting on the back of the compressor is little more than finger tight. 3 ft lbs !!!. do not overtighten or it will leak.
Turn over compressor by hand to get the oil you put in it to lubricate the inside and outa the way (liquids don't compress too well).
Pull a vacuum on it for a few hours. This serves two purposes, check for leaks (if pressure goes up it leaks) and causes any water to boil off. Water in the system will freeze and block the system, hello failed compressor, so you gotta get it out.
I used a venturi type vac pump. worked well.
Now charge the system. Fill to about 85% of the charge required for R12. This means about 28 oz of 134 or two 14 oz bottles for the mathematically challenged!!
First you gotta get some 134 into the system, connect bottle to lo side, it should take most of a bottle due to the vacuum in there. You can force more in by warming the 134 can in a bucket of hot water.
Once you have some 134 in there you can run the engine, turn the ac on max and it should cycle the ac cluch and pull the pressure down on the low side, Once the lo side pressure drops it will take another can or so of 134.
Once it is all done it should not cycle too quickly. You can adjust the switch on the accum 1/8 turn counter clockwise (I think) to drop the low side pressure from 26 (for R12) to about 22 PSI for 134. It should then cycle between 22 and 46 PSI on the load side.
Hi side pressure depends on ambient temperature.
Check the static pressure after a couple of days, if it drops, you may have a leak in which case it is leak detector time.
Plenty of info in the forum and in the Ogre's cave.
Take a look at my web site as well.
Dave http://www.ltlfrari.com
