AC recharge with r134 problems

[Another911]

I’m having difficulty getting r134 refrigerant in the AC system. I’m recharging an ‘84 and ‘89, both of which were converted to r134 in last two years. I’ve vacuumed both systems to -29 PSI, and both are holding the vacuum for at least a few hours. I am connecting the r134 cans to the manifold yellow source hose with an adaptor on the can, open the can valve filling the hose, then bleed the air out of the yellow source hose. Turn the AC and blower on full. Compressors are coming on, then open up blue low-end valve on manifold to start charging. I am getting 6sh oz out of the first 12 oz can over a 5-10 minute period. After that the discharge rate on the can comes to snails pace while both the low and high end pressure rise to very high ranges 50 and 300+. The ambient temp has been hot around 95F degrees. Increasing the rpms helps a little, but still slow. Am I just impatient, or has anyone else had issues getting the compressor to pull in 30+ oz of refrigerant? Do some refrigerant brands work better than others? Help😩

[walt]

You can put the can in some warm water, that will speed things up a bit. Make sure your valves are wide open. Usually that 1st can goes pretty quick.

[Rawknees'Turbo]

Another thing you can do to heat the can is set it in front of the exhaust tip, if your charge hose reaches. Also, you can swirl the can in your hand and momentarily tip it sideways to speed up the flow.

How long did you pull a vacuum with the pump? With a 911, it is a good idea to run at least 3 hours of pumping time (sounds kinky, I know! ) to ensure removing all water/water vapor in the system, due to the many feet of hose, far away components location, etc. Also, the industry standard for system vacuum holding is 20-30 minutes, just for a FYI.