As a technician, I always used a Matco HD booster that I had. Bought it in 2004 and used it until 2007 at which time I sold it and went back to school to get my degree to become an RN. Worked like a charm and never once had a single problem with it in those 3 years. Was a bit expensive but they are worth it. They may cost around 4 to 5 hundred new, but I am sure you can get a used one somewhere. Just not from me. lol