My plan was to add one can of R134a to the AC system if it would take it. Well, it did and two more cans after that and I'm pretty sure I could have added even more! I'm hoping there's not a leak, but the system was never as cold as I felt it should have been, so I'm guessing it was not actually full when my mechanic finished. He did say he wasn't sure it had enough refrigerant. Also had to replace the compressor drive belt too. Didn't end up doing much with the speed control this time so next time...