How Do I Know What Pressures Should Be When Converting From R12 to R134a

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AC, R12 to R134 Conversion Questions

• Thread starter Shawn
• First date Nov 15, 2009

• #1

Seems similar something is wrong nonetheless. This is the adapter on the high side schraeder valve and the hose one of the cans of R134. The bluish hose goes to the gauge and is attached to the dryer shown.

The Yellow hose goes to the vacuum.

Merely what practice I exercise with the red hose? No more valves bachelor.

Leave the ruby hose off, put vacuum on till effectually 29 hg with the bluish valve open? Close the blueish valve and outset installing the R134 after information technology seems like in that location are no leaks by installing the small hose on the adapter on the high side? Run the car afterwards 3.2 cans in and encounter if it works? I guess at the .2 corporeality for the last tin can past giving it merely a quick squirt of the last can and the rest goes in the atmosphere because I have to pull information technology off the schraeder adapter?

• #ii

the red hose is for the low side plumbing equipment and the blue is for the high side.what you desire to do is claw those up and then hook the yellow to the vac. pump open the gauges allow it pull vac. for about half an 60 minutes and so close the gauges turn vac off and let it sit for half an 60 minutes and meet if it holds vac. if it does then hook the yellow hose to the can you volition demand some other tool you can get it at any parts shop it pinchs the can and put a hole in it. and so open your gauges and let it run in y'all may need to start the motorcar but make sure you close the cherry judge first hope this helps

• #3

the red hose is for the low side fitting and the blue is for the high side.

it sounds like yous know what your doing BUT, the scarlet hose and cuff is the high pressure or liquid supply line ( in layman'southward terms the smaller line) and the blue is for the low pressure suction or vapor side

• #iv

• #5

The gages are from originally an R12 system, are the vacuum pressures dissimilar where I need to go become specific R134 gages? I thought vacuum was vacuum.

• #6

The gages are from originally an R12 system, are the vacuum pressures unlike where I need to go get specific R134 gages? I thought vacuum was vacuum.

no , yous simply accept the potential to contaminate the organisation with remainder 12 . and one matter, utilize a glove or a rag when connecting and disconnecting the liquid line hose as the temp of r 134 is negative 14 degrees Fahrenheit at 0 psi

• #7

This is a R12 gauge set.
Run across the Screw ON Hose ends.

This is a R134a Gauge set up.
Note the SNAP ON Hose ends.

Blue Hose is the LOW Side, Suction Side. Smaller DIA nipple fitting.

Xanthous Hose goes to the Vacuum pump, the Freon can, Charging Cylinder ETC.

RED Hose is the High side, Discharge. Larger DIA nipple Fitting.

Because the Hose connections on the R134a gauge set are Quick connects, Much like the same ones on air tools merely with sealing valves NOTE the Tops on the Blue and Red quick-connects, those thumb-wheels are sealing valves.
You lot'll exist safe putting them on or taking them off.

You must apply remove the schrader valve where you accept the BLUE hose attached now. Spiral on the R134a Adapter. Do the SAME matter with the Loftier Side port. Connect the R134a hose set and evacuate. The accuse it with iii 12 oz cans. That should get you close to 33-35 ounces. Add near 1/2 can by guesstimate. Close your valves and exam. That should have you at about 38 oz full.

• #8

Cheers for all the input. Didn't know about the -14 degrees. Now what virtually the 3.2 cans, how practise I get .2 in then the can is open so isn't it open and never to be closed where information technology now escapes into the atmosphere when I pull it off after guessing at .2. It said to not clean out the compressor and I did non, I simply put new ester oil in, 10oz, the oil was already out since I got the compressor from the wrecking yard. When I put the vacuum on, isn't it going to effort and pull out the ester oil?

Hhott but piped in earlier I posted on the volume. Cheers.

Last edited: November sixteen, 2009

• #nine

You must utilise remove the schrader valve where you lot have the BLUE hose attached at present. Screw on the R134a Adapter. Do the Aforementioned thing with the HIGH Side port. Connect the R134a hose set and evacuate. The charge it with three 12 oz cans. That should go you shut to 33-35 ounces. Add about 1/2 can by guesstimate. Shut your valves and exam. That should have you at about 38 oz total.Hhott71

Dryer is new for R134 with 134 size fitting but not quick release, simply I recall the adapter kit had adapter for this equally well every bit the quick release for the high side. I volition look when I get domicile. Now I'll go get 134 hoses and see what information technology has. Trudging forward to larn how this goes. Are the loftier and depression quick disconnects two dissimilar sizes?

The

• #ten

Vacuum held all night, only demand to get the right attachment so the freon tin go in the yellowish tube and all should work. My inexpensive switch-over to salve some mulah has gone from it shouldn't be over 150.00 to near 300.00, which is how much the AC company was going to accuse to fill it with R12. But now I know how it works and have some of the tools.

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Source: https://nastyz28.com/threads/ac-r12-to-r134-conversion-questions.169583/

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